Quiz: Mechanical Engineering 9th July 2020

Quiz: Mechanical Engineering
Exam: UPPSC AE
Topic: Miscellaneous

Each question carries 3 mark.
Negative marking: 1 mark
Time: 10 Minute

Q1. In regarding nucleate boiling ___________
(a) The temperature of the surface is greater than the saturation temperature of the liquid
(b) Bubbles are created by expansion of entrapped gas or vapour at small cavities in the surface
(c) The temperature is greater than that of film boiling
(d) All options are correct

Q2. Calculate the power (in kW) required by the engine of a car travelling at the constant speed of 50 m/s. If the car has to resist a wind drag F_D=20V(in N), where V is the velocity of the car.
(a) 20
(b) 25
(c) 50
(d) 75

Q3. Water, by evaporating cooling, can be theoretically be cooled down to
(a) Atmospheric temperature
(b) Air dry bulb temperature
(c) Air wet bulb temperature
(d) Air dew point temperature

Q4. What is the location of frictional force when the intensity of pressure is uniform in a flat pivot bearing having radius r?
(a) r
(b) r/2
(c) 2r/3
(d) r/3

Q5. When the depth of water in an open channel is less than the critical depth, then flow is said to be
(a) critical
(b) turbulent
(c) torrential
(d) tranquil

Q6. In order that no shock wave develops when flow is taking place through a converging-diverging tube, Mach number at exit should be
(a) equal to 1
(b) greater than 1
(c) less than 1
(d) none of these

Q7. Which of the following is the correct method for the conversion of spring-controlled governor from unstable to stable?
(a) Increasing the ball weight
(b) Decreasing the spring stiffness
(c) Decreasing the ball weight
(d) Increasing the spring stiffness

Q8. Which one of the following assumptions in the theory of pure torsion is false?
(a) The angle of twist is uniform along the length
(b) The shaft is of uniform circular section throughout
(c) Cross-section plane before torsion remains plane after torsion
(d) All radii get twisted due to torsion

Q9. Filling or decking in a cooling tower increases the rate of heat transfer by providing
(a) increased flow of water
(b) increased flow of air
(c) increased flow of water and air
(d) a large amount of wetted surface

Q10. Two-stroke engines are used more frequently in two wheelers due to which of the following reasons?
(a) exhaust is less
(b) higher thermal efficiency
(c) higher power to weight ratio
(d) less friction

Solutions

S1. Ans.(a)
Sol. Nucleate boiling is a type of boiling that takes place when the surface temperature is hotter than the saturated fluid temperature by a certain amount but where the heat flux is below the critical heat flux.

S2. Ans.(c)
Sol. We know that
Power required = F_D×V
= 20×V×V
= 20×50^2
= 50 kW

S3. Ans.(c)
Sol. By evaporating cooling, air can be cooled down to its wet bulb temperature. Evaporative cooling is a process that uses the effect of evaporation as a natural heat sink. Sensible heat from the air is absorbed to be used as latent heat necessary to evaporate water.

S4. Ans.(c)
Sol. The frictional force acts at 2r/3 distance from the center when intensity of pressure is given uniform.

S5. Ans.(c)
Sol. When the depth of water in an open channel is less than the critical depth, then flow is said to be torrential.

S6. Ans.(b)
Sol. Mach number at exit should be greater than 1 for no shock wave generation when flow is taking place through a converging-diverging tube.

S7. Ans.(b)
Sol. A spring-controlled governor is said to be stable if the radius of the balls increases with increase in the speed of the governor and vice versa. A spring-controlled governor can be made stable by decreasing the spring stiffness.

S8. Ans.(a)
Sol. Following assumptions are made in the theory of pure torsion:
The material of shaft is uniform throughout
The shaft is of uniform circular cross-section throughout its length
Cross section remains plane before and after torsion.
All radii get twisted due to torsion

S9. Ans.(d)
Sol. Filling or decking in a cooling tower increases the rate of heat transfer by providing increased wetted area.

S10. Ans.(c)
Sol. Two-stroke engines are used more frequently in two wheelers due to higher power to weight ratio of these engines.

Quiz: Civil Engineering 4 july 2020

Quiz: Civil Engineering
Exam: UPSSSC-JE
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes

Q1. Stress-strain curve of concrete is
(a) a perfect straight line upto failure
(b) straight line upto 0.002% strain value and the parabolic upto failure
(c) hyperbolic upto 0.002% strain value and a straight line upto failure
(d) parabolic upto 0.002% strain value and a straight line upto failure

Q2. The moisture content of the soil, after free drainage has removed most of the gravity water, is called
(a) Available moisture
(b) Saturation capacity
(c) Field capacity
(d) Gravity water

Q3. While estimating for plastering, usually no deduction is made for –
(a) Ends of beams
(b) Small opening upto 0.5 sq. m.
(c) End of rafters
(d) All the above

Q4. Maximum shear stress produced on a solid circular shaft under torque is:
(a) 16T/(πD^4 )
(b) 16T/(πD^3 )
(c) 32T/(πD^4 )
(d) 32T/(πD^3 )

Q5. The surveying used to determine additional details such as boundaries of fields, is called :
(a) City surveying
(b) Location surveying
(c) Cadastral surveying
(d) Topographical surveying

Q6. A self-cleansing velocity may be defined as that velocity at which the solid particles will:
(a) Settle at the bottom of the sewer
(b) Remain in suspension, without settling at the bottom of the sewer
(c) Wash out from the sewer
(d) Cause damage to the sewer

Q7. The ratio of different ingredients (cement sand, aggregate) in concrete mix of grade M20, is
(a) 1:1:2
(b) 1:11/2 :2
(c) 1: 2: 4
(d) 1: 3 : 6

Q8. The term soil mechanics was coined by
(a) Rankine
(b) Newton
(c) Terzaghi
(d) Newmark

Q9. Fish plate is in contact with rail at
(a) Web of rail
(b) Fishing plane
(c) Head of rail
(d) Foot of rail

Q10. Minimum pitch of rivets shall not be less than
(a) 1.5 d
(b) 2.0 d
(c) 2.5 d
(d) 3.0 d

SOLUTION

S1. Ans.(d)
Sol. According to IS. Code stress strain curve is parabola up to 0.002 then straight line
Up to failure.

S2. Ans.(c)
Sol. The moisture content of the soil, after free drainage has removed most of the gravity water, is called field capacity.

S3. Ans.(d)
Sol.
Plastering is measured in terms of m². If,
(a) opening area < 0.5 m² (No deduction is applied)
(b) opening area is between 0.5 m² – 3m², then (single side deduction is applied)
(c) opening area > 3 m², then (double side deduction is applied)

S4. Ans.(b)
Sol. T/J=τ_max/R
τ_max=JR/J
= (T×D/2)/(πD^4/32)
τ_max=16T/πD³

S5. Ans.(c)
Sol. cadastral surveying is used to determine additional details such as boundaries of fields & also used for calculating the Area of Land.

S6. Ans.(b)
Sol. A self-cleansing velocity may be defined as that velocity at which the solid particles will remain in suspension, without settling at the bottom of the sewer.

S7. Ans.(b)

Sol. Nominal mix for different grade of concrete as below.

Concrete Grade Mix ratio
M 7.5 1:4:8
M 10 1:3:6
M 15 1:2:4
M 20 1:1.5:3
M 25 1:1:2

S8. Ans.(c)
Sol. Karl terzaghi is father of soil mechanics. His first book on soil mechanics is erbdomechanics published in 1925.

S9. Ans.(b)
Sol. fish plate is in contact with rail at fishing plane.

S10. Ans.(c)
Sol. → minimum pitch of rivet = 2.5d
→ maximum pitch for compression = (12t,200)_minimum
→ maximum pitch for tension = (16t,200)_minimum

Quiz: Civil Engineering 30 june 2020

Quiz: Civil Engineering

Exam: UPSSSC-JE

Topic: Miscellaneous

 

Each question carries 1 mark

Negative marking: 1/4 mark

Time: 10 Minutes

 

Q1. M-50 is considered as _________ type of concrete.

(a) Ordinary

(b) Standard

(c) High strength

(d) All of the above

 

Q2. One cubic meter of mild steel weights about?

(a) 12560 kg

(b) 3625 kg

(c) 1000 kg

(d) 7850 kg

 

Q3. According to WHO, what is the permissible chloride content in drinking water?

(a) 0.001 mg/l

(b) 1 mg/l

(c) 250 mg/l

(d) 350 mg/l

 

Q4. Which of the following is not a form of precipitation?

(a) Snow

(b) Rain

(c) Hail

(d) Smog

 

Q5. The distance between the midpoint of the long chord to the midpoint of curve is known as ___________.

(a) cub chord

(b) normal

(c) mid ordinate

(d) long chord

 

Q6. Spacing between lateral ties of RCC columns should not exceed:

(a) 150 mm

(b) 250 mm

(c) 300 mm

(d) 500 mm

 

Q7. Consistency limit measured by the instrument, is known as:

(a) Plate load test

(b) Oedometer

(c) Casagrande’s apparatus

(d) Hydrometer

 

Q8. Which one of the following assumptions of Bernoulli’s theorem is not correct?

(a) Flow should not be unsteady

(b) Flow should be continuous

(c) The fluid should be compressible

(d) Flow should be frictionless

 

Q9. The allowable stress in a long column can be increased by increasing the

(a) radius of gyration

(b) eccentricity

(c) slenderness ration

(d) length of the column

 

Q10. The penetration test on bitumen is used for determining its

(a) Grade

(b) Ductility

(c) Viscosity

(d) None of these

 

SOLUTION

 

S1. Ans.(b)

Sol.

Concrete Grade Type of concrete
M10 – M20 Ordinary
M25 – M55 Standard
M60 – M80 High strength

 

S2. Ans.(d)

Sol. Density of mild steel is about 7850 kg/m³. hence One cubic meter of mild steel weights about 7850 kg.

 

S3. Ans.(c)

Sol. according to WHO, the permissible limit of chloride content in drinking water is 250 mg/l.

 

S4. Ans.(d)

Sol. There are some forms of precipitation-

  • Rainfall
  • Drizzle
  • Glaze
  • Snow
  • Sleet
  • Hails

 

S5. Ans.(c)
Sol. Distance between mid point of curve (C) to mid point of long chord (D) is known as mid ordinate (versed sine) of the Curve.
▭(CD=R-R cos⁡〖∆/2 〗 )

 

S6. Ans.(c)

Sol. Spacing between lateral ties

Maximum spacing should not be greater than.

  • 16×minimum diameter of bar
  • Least lateral dimension
  • 300 mm.

 

S7. Ans.(c)

Sol. Consistency limit is measured by Casagrande’s apparatus.

 

S8. Ans.(c)

Sol. There are some assumptions for Bernoulli’s theorem

(1)  The flow is steady.

(2)  The flow is incompressible.

(3)  The flow is frictionless

(4)  The flow continuous

(5)  The flow should be irrotational or rotational along streamline.

 

S9. Ans.(a)
Sol. The allowable stress in a long column can be increased by increasing it’s radius of gyration and radius of gyration depends on moment of inertia.
R=√(I/A)
R- radius of gyration
I- Moment of Inertia

 

S10. Ans.(a)

Sol. The penetration test on bitumen is used for determining the Grade of bitumen.

 

 

 

 

 

 

 

Quiz Electronics Engineering 12 June 2020

Quiz Electronics Engineering
Exam: NIC
Topic: Miscellaneous
Date: 12/06/2020

Each Question carries 1 Mark
Negative Marking: 1/4
Time: 10 Minutes

Q1. How many RAM chips of size (256 K × 1 bit) are required to build 1 MB memory?
(a) 8
(b) 10
(c) 24
(d) 32
L1 Difficulty 2
QTags Digital Electronics
QCreator Vikram Kumar

Q2. A hash-function f defined as f(key) = key mod 7, with linear probing, insert the keys 37, 38, 72, 48, 98, 11, 56, into a table indexed from 11 will be stored in the location
(a) 3
(b) 4
(c) 5
(d) 6
L1 Difficulty 3
QTags Computer
QCreator Vikram Kumar

Q3. The CFG s ⟶ as | bs | a | b is equivalent to regular expression
(a) (a + b)
(b) (a + b)(a + b)*
(c) (a + b)(a + b)
(d) All of these
L1 Difficulty 2
QTags Compiler Design
QCreator Vikram Kumar

Q4. In a Single Pass Assembler, most of the forward references can be avoided by putting the restriction
(a) on the number of strings/lifereacts
(b) that the data segment must be defined after the code segment
(c) on unconditional rump
(d) that the data segment be defined before the code segment
L1 Difficulty 3
QTags Compiler Design
QCreator Vikram Kumar

Q5. The file structure that redefines its first record at a base of zero uses the term
(a) relative organization
(b) key fielding
(c) dynamic reallocation
(d) All of these
L1 Difficulty 3
QTags Data Structure
QCreator Vikram Kumar

Q6. For a database relation R(a, b, c, d), where the domains of a, b, c, d include only atomic values, only the functional dependencies and those that can be inferred from them hold:
a ⟶ c ; b ⟶ d ; the relation is in
(a) first normal form but not in second normal form
(b) second normal form but not in third normal form
(c) third normal form
(d) None of the above
L1 Difficulty 3
QTags DBMS
QCreator Vikram Kumar

Q7. The extent to which the software can control to operate correctly despite the introduction of invalid input is called as
(a) reliability
(b) robustness
(c) fault tolerance
(d) portability
L1 Difficulty 3
QTags Software Engineering
QCreator Vikram Kumar

Q8. A packet-switching network
(a) is free
(b) can reduce the cost of using an information utility
(c) allows communication channel to be shared among more than one user
(d) both (b) and (c)
L1 Difficulty 3
QTags Networking
QCreator Vikram Kumar

Q9. When signed numbers are used in binary arithmetic, then which of the following notations would have unique representation for zero?
(a) Sign-magnitude
(b) 1’s complement
(c) 2’s complement
(d) 9,s complement
L1 Difficulty 3
QTags Computer Organization & Microprocessor
QCreator Vikram Kumar

Q10. The data-bus width of a 2048 x 8 bits is
(a) 8
(b) 10
(c) 12
(d) 16
L1 Difficulty 1
QTags Digital Electronics
QCreator Vikram Kumar

SOLUTIONS

S1. Ans.(d)
Sol.
Memory capacity = 1 MB = 2^20 bytes = 2^20 × 8 bits = 2^23 bits
RAM chip size = 256 K × 1 bit = 2^18 bits
Now, Number of RAM chips are = 2^23/2^18 = 2^5 = 32

S2. Ans.(c)
Sol. Hash function = f(key) = key mod 7
Insertion order is 37, 38, 72, 48, 98, 11, 56
Step 1: Insert 37 ⇒ 37 mod 7 = 2. It occupies 2nd location.
Step 2: Insert 38 ⇒ 38 mod 7 = 3. It occupies 3rd location.
Step 3: Insert 72 ⇒ 72 mod 7 = 2, but 2nd location already occupied, so after linear probing it would occupy 4th location.
Step 4: Insert 48 ⇒ 48 mod 7 = 6. It occupies 6th location.
Step 5: Insert 98 ⇒ 98 mod 7 = 0. It occupies 0th location.
Step 6: Insert 11 ⇒ 11 mod 7 = 4, but 4th location already occupied, after linear probing it would get into 5th location.

S3. Ans.(b)

(a + b)(a + b)*

S4. Ans.(d)
Sol. A single pass assembler scans the program only once and creates the equivalent machine codes. Data segment must be defined before the code segment to avoid forward references.

S5. Ans.(a)
Sol. A relative file is a file in which each record is identified by its ordinal position in the file (record 1, record 2 and so on). This means that records can be accessed randomly as well as sequentially. If defined Access Mode is Dynamic then file can be accessed both sequentially and randomly.

S6. Ans.(a)
Sol. If every attribute in a relation is single valued attribute then it is in 1NF.
candidate key of above relation is ab.
Since all a, b, c, d are single valued attribute so the relation is in 1 NF.
a ⟶ c and b ⟶ d are partially dependent so they are not in 2 NF.
Therefore, the relation is in first normal form but not in second normal form.

S7. Ans.(b)
Sol. Robustness is the ability of a computer system to withstand errors during execution and invalid input. It focuses on handling unexpected termination and unexpected actions.

S8. Ans.(d)

-can reduce the cost of using an information utility
-allows communication channel to be shared among more than one user

S9. Ans.(c)
Sol. In 1’s complement, 9’s complement and sign-magnitude zero is represented in more than one notation but in 2’s complement it is represented in only 1 way.

S10. Ans.(a)

8

Quiz: Civil Engineering 12 june 2020

Quiz: Civil Engineering
Exam: Telangana PSCM
Topic: Building, Material & Construction

Each question carries 1 mark
Negative marking: No negative marking
Time: 10 Minutes

Q1. For manufacturing coloured glass, the colouring pigments are added in the glass at the stage of
(a) Raw material mixing
(b) Fusion
(c) Melting
(d) Finishing

Q2. Most commonly used ingredients in cement manufacturing is:
(a) Graphite
(b) Lime stone
(c) Sand stone
(d) Slate

Q3. The most commonly used base for timber painting is
(a) Red lead
(b) Zinc white
(c) White lead
(d) Titanium white

Q4. In which of the following direction the strength of timber is maximum?
(a) Parallel to grains
(b) 45° to grains
(c) Perpendicular to grains
(d) Same in all directions

Q5. Which of the following quality of timber can improved using Abel’s process?
(a) Durability
(b) Fire Resistance
(c) chemical resistance
(d) Strength

Q6. The small area on painted surface enclosed by hair line cracks are known as:
(a) Blistering
(b) Crazing
(c) Wrinkling
(d) Chalking

Q7. Water cement ratio is usually expressed in:
(a) Litres of water required per bag of cement
(b) Litres of water required per kg of cement
(c) m³ of water required per bag of cement
(d) m³ of water required per kg of cement

Q8. If the rocks are formed due to alteration of original structure under heat and excessive pressure, then they are known as _________.
(a) Igneous
(b) Sedimentary
(c) Volcanic
(d) Metamorphic

Q9. The operation of converting limestone into quicklime by heating it to temperature upto 900°C and releasing carbon dioxide is known as:
(a) Charging
(b) Calcination
(c) Drawing
(d) Hydrating

Q10. Tensile strength of concrete is measured by
(a) direct tension test in the universal testing machine
(b) applying compressive load on the diameter of cylinder
(c) applying third point loading on a prism.
(d) applying tensile load along the diameter of cylinder.

SOLUTION

S1. Ans.(b)
Sol. Colour pigment is added in the manufacturing of glass at the stage of fusion.

S2. Ans.(b)
Sol. lime is most important ingredient in manufacturing of cement. It is about 62-65% in cement. Lime is act as binding material in cement.

S3. Ans.(c)
Sol. White lead is used as base for timber painting.

S4. Ans.(a)
Sol. if applied load is parallel to grains then the strength of timber is maximum.

S5. Ans.(b)
Sol. Timber surface is coated with solution of sodium silicate (Na_2 SiO_3 ) which increase the resistance against fire. This process is called sir Abel’s process.

S6. Ans.(c)
Sol. Wrinkling → These are the hair line cracks on small area of painted surface.

S7. Ans.(a)
Sol. Water Cement ratio is usually expressed in liters of water required per bag of cement.
▭(water-cement ratio= (weight of water)/(weight of cement))

S8. Ans.(d)
Sol. Metamorphic rocks are formed by the change in character of the original rocks when they are subjected to great heat and pressure.

S9. Ans.(b)
Sol. Calcination is a process of heating the limestone up to redness.
CaCO_3—– Calcination/(900°C)—– CaO + CO_2
S10. Ans.(a)
Sol. Tensile strength of concrete is measured by direct tension test in the universal testing machine.

Quiz: Electrical Engineering 11 June 2020

Quiz: Electrical Engineering

Exam: UPSSSC JE

Topic: Miscellaneous

 

Each question carries 1 mark.

Negative marking: 1/4 mark

Time: 10 Minute

 

Q1. EMF of a thermo couple depends upon the

(a) nature of material of metal

(b) difference of temperature of two junctions

(c) both (a) and (b)

(d) none of the above

 

 

Q2. If the diameter of a copper wire is increased by two times keeping the terminal voltage same then the drift velocity will

(a) become twice

(b) become half

(c) become four time

(d) remain unchanged

 

 

Q3. According to classical free electron theory, electrons in a metal are subjected to

(a) constant potential

(b) sinusoidal potential

(c) square-wave potential

(d) non-periodic potential

 

 

Q4. In ionic crystal, electrical conductivity is

(a) very high

(b) depends on material

(c) depends upon temperature

(d) practically zero

 

 

Q5. What type of defect causes F-centers in a crystal?

(a) Stoichiometric defect

(b) Metal excess defect due to anion vacancies

(c) Metal excess defect due to extra cation

(d) Frenkel defect

 

 

Q6. In crystal lattice, what are the vacancies created by the absence of certain atoms known as

(a) Hertz defects

(b) Schottky defects

(c) Pauli defects

(d) Crystal defects

 

 

Q7. Superconducting metal in superconducting state has relative permeability of

(a) more than one

(b) one

(c) zero

(d) negative

 

 

Q8. The dc resistivity and permeability exhibited by a type 1 superconductor are respectively

(a) zero and zero

(b) zero and unity

(c) unity and zero

(d) unity and unity

 

 

Q9. What is the magnetic susceptibility χ of an ideal superconductor?

(a) 1

(b) -1

(c) 0

(d) infinite

 

 

Q10. Which effect is the converse of Peltier effect?

(a) Seebeck effect

(b) Thomson effect

(c) Hall effect

(d) joule effect

 

Solutions

S1. Ans. (c)

Sol. EMF of a thermo couple depends upon both factors

  • nature of material of metal
  • difference of temperature of two junctions

 

S2. Ans. (d)

Sol. It will remain unchanged

 

S3. Ans. (a)

Sol. constant potential

 

S4. Ans. (d)

Sol. In ionic crystal, electrical conductivity is practically zero.

 

S5. Ans. (b)

Sol. Metal excess defect due to anion vacancies

 

S6. Ans. (b)

Sol. Schottky defects

 

S7. Ans. (c)

Sol. Zero

 

S8. Ans. (a)

Sol. Zero and zero

 

S9. Ans. (b)

Sol. -1

 

S10. Ans. (a)

Sol. Seebeck effect

 

 

 

Quiz: Mechanical Engineering 8 June 2020

Quiz: Mechanical Engineering
Exam: UPSSSC JE
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/3 mark
Time: 10 Minutes
Q1. A metal block is thrown into deep lake. As it sinks deeper in water, the buoyant force acting on it
(a) increases
(b) remains the same
(c) decreases
(d) first increases and then decreases

Q2. Which of the following statements is wrong?
(a) Streamlines cannot start or end anywhere except at the interface or infinity.
(b) Streamline spacing varies directly as the flow velocity.
(c) Streamlines can meet at a stagnation point where the velocity is zero.
(d) The flow is only along the streamline and not across it.

Q3. In a Carnot engine, when working substance gives heat to the sink
(a) temperature of the sink increases
(b) temperature of the sink remains same
(c) temperature of the source decreases
(d) temperature of both the sink and source decreases

Q4. Three engines A, B and C operating on Carnot cycle respectively use air, Nitrogen and Argon as the working fluid. If all the engine operates within the same temperature limit, then which engine will have highest efficiency.
(a) Engine A
(b) Engine B
(c) Engine C
(d) All engines will have same efficiency

Q5. When a system is in equilibrium, any conceivable change in entropy would be
(a) maximum
(b) zero
(c) positive
(d) negative

Q6. Which of the following is false statements?
Some of the methods used to reduce diesel smoke are as follows
(a) using additives in the fuel
(b) engine derating i.e. reducing the maximum flow of fuel
(c) increasing the compression ratio
(d) avoidance of overloading

Q7. The instrument preferred in the measurement of highly fluctuating velocities in air flows is
(a) Pitot-static tube
(b) Propeller type anemometer
(c) Three cup anemometer
(d) Hot wire anemometer

Q8. Perpetual motion machine of second kind violates the
(a) First law of thermodynamics
(b) Kelvin-Planck statement
(c) Clausius statement
(d) Third law of thermodynamics

Q9. Second law of thermodynamics defines
(a) Heat
(b) Work
(c) Enthalpy
(d) Entropy

Q10. Consider the following statements pertaining to large heat transfer rate using fins
1. Fins should be used on the side where heat transfer coefficient is small.
2. Long and thick fins should be used.
3. Short and thin fins should be used.
4. Thermal conductivity of fin material should be large.
Which of the above statements are correct?
(a) 1, 2 and 3
(b) 1, 2 and 4
(c) 2, 3 and 4
(d) 1, 3 and 4

SOLUTION

S1. Ans (b)
Sol. As buoyant force depends only on the displaced volume of fluid by the submerged or floating body according to Archimedes principle. So, volume displaced by the metal block will remain constant from when it sinks in the fluid till it sinks deeper, hence, the buoyant force on the metal block remains same.

S2. Ans (b)
Sol. Streamline spacing is inversely proportional to the velocity, it means for accelerated flow spacing between streamlines is less and for retarded flow, this spacing will be more.

S3. Ans (b)
Sol. When working substance gives heat to the sink then its temperature remains same
because sink and source both are considered as reservoir of heat.

S4. Ans (d)
Sol. As efficiencies of Carnot engines working between same temperature limits do not depend upon working fluid of engines.
So, engine A, B and C all three will have same efficiency.

S5. Ans (b)
Sol. When a system is in equilibrium, any conceivable change in entropy would be zero.
Because when a system reaches in equilibrium state then its entropy will be maximum at that state.

S6. Ans (c)
Sol. Increasing the compression ratio is not recommended to reduce diesel smoke as it increases the weight of the engine and cost which is not worthy for reducing diesel smoke.

S7. Ans (d)
Sol. Hot wire anemometer is used for the measurement of highly fluctuating velocities in air. This can be done by measuring the heat loss of the wire which is placed in the fluid stream. The wire is heated by electrical current. The hot wire when placed in the stream of the fluid, in that case, the heat is transferred from wire to fluid, and hence the temperature of wire reduces. The resistance of wire measures the flow rate of the fluid which is the function of heat loss from the wire and change in the resistance of wire.

S8. Ans (b)
Sol. Perpetual motion machine of the second kind is a machine which produces work while exchanging heat from a single heat source. Which violates Kelvin-Planck statement of Second law of thermodynamics.

S9. Ans (d)
Sol. Second law of thermodynamics defines Entropy or energy degradation.
As second law of thermodynamics states that Heat (low grade energy) cannot be converted into work (high grade energy) completely because it violates Kelvin-Planck statement.

S10. Ans (d)
Sol. Fins are used where thermal conductivity of material is high and coefficient of heat transfer is small. We should use short and thin fins to increase heat transfer area exposed to environment.

Quiz: Civil Engineering 5 june 2020

Quiz: Civil Engineering
Exam: UPSSSC-JE
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes

Q1. Granite is a rock that is by nature:
(a) Metamorphic
(b) Volcanic
(c) Plutonic
(d) Sedimentary

Q2. Which one of the following pairs is INCORRECTLY matched?
(a) Air Valve – to check the water flow in pipes, in the directions
(b) Check valve – To release the accumulated air in pipelines.
(c) Scour valve – To drain or empty the pipe line section
(d) Surge arrestor – control of water hammer in pipe lines

Q3. The item of the brick structure measured in sq. m is
(a) Broken glass coping
(b) Brick work in arches
(c) Reinforced brick work
(d) Brick edging

Q4. The penetration test on bitumen is used for determining its
(a) Grade
(b) Ductility
(c) Viscosity
(d) None of these

Q5. There will be no tension in the dam if the resultant passes through the
(a) last third
(b) middle third
(c) middle two-third
(d) none of the above

Q6. Reinforced concrete Slab act as
(a) Rigid diaphragm
(b) Flexible diaphragm
(c) Brittle diaphragm
(d) None of the above

Q7. Seepage pressure always acts
(a) in the direction opposite to flow
(b) in the direction of flow
(c) in the direction perpendicular to flow
(d) in all the direction

Q8. In case of principal axis of a section
(a) sum of moment of inertia is zero
(b) difference of moment of inertia is zero
(c) product of moment of inertia is zero
(d) None of these

Q9. Agonic line passes through the points of:
(a) Equal declination
(b) Zero declination
(c) Equal dip
(d) Equal bearing

Q10. Specific weight of sea water is more than that of pure water because it contains
(a) dissolved air
(b) Dissolved salt
(c) Suspended matter
(d) all options are correct

SOLUTION

S1. Ans.(c)
Sol. →Granite is a plutonic rock, also known as ‘intrusive Igneous rock’.
→ it is hard and durable hence is suitable for building piers.

S2. Ans.(b)
Sol. Check value or reflux valve or non-returning valves are allows the flow only in one direction only back flow is not permitted.

S3. Ans.(a)
Sol. Broken glass coping measured in terms of square meter while reinforced brick work measured in terms of cubic meter.

S4. Ans.(a)
Sol. The penetration test on bitumen is used for determining the Grade of bitumen.

S5. Ans.(b)
Sol. If the resultant of all the forces passes from the middle third portion from the base then there will be no tension in the dam.
▭(e≤b/6)
Where, e= eccentricity
b= width of dam section

S6. Ans.(a)
Sol. Reinforced concrete slab act as a rigid diaphragm.

S7. Ans.(b)
Sol. seepage pressure always acts in the direction of flow.

S8. Ans.(c)
Sol. An object rotating about an axis, the resistance of a body to accelarate is called inertia of mass. In case of principal axis of a section the product of moment of Inertia is zero.

S9. Ans.(b)
Sol. Agonic line – line connecting 0° declination angle
Isogonic line – line connecting same declination angle.
Isoclinic line – line connecting same angle of dip
Aclinic line – line connecting 0° dip angle.

S10. Ans.(d)
Sol. All options are correct, we all are aware already with this fact that sea water contains dissolved salt, dissolved air and some suspended matters which increase its specific weight as compare to pure water.

Quiz Electronics Engineering 2 June 2020

Quiz Electronics Engineering
Exam: NIC
Topic: Miscellaneous
Date: 02/06/2020

Each Question carries 1 Mark
Negative Marking: 1/4
Time: 10 Minutes

Q1. A class member declared protected in Java becomes member of subclass of which type?
(a) Public Member
(b) Protected Member
(c) Private Member
(d) Static Member

Q2. How many full adders are required to construct an m-bit parallel adder?
(a) m
(b) m – 1
(c) m/2
(d) m + 1

Q3. Which type of traversal of binary search tree outputs the value in sorted order?
(a) Pre-order
(b) In-order
(c) Post-order
(d) Level-order

Q4. A positive AND gate is also a negative
(a) NAND gate
(b) OR gate
(c) AND gate
(d) NOR gate

Q5. Events A and B are mutually exclusive and have non-zero probability. Which of the following statement is TRUE?
(a) P(AUB) = P(A) + P(B)
(b) P(B’) > P(A)
(c) P(A∩B) = P(A)P(B)
(d) P(B’) < P(A)

Q6. Assume transaction A holds a shared lock R. If transaction B also requests for a shared lock on R. It will
(a) result in deadlock situation
(b) immediately be granted
(c) immediately be rejected.
(d) None of the above

Q7. Web links are stored within the page itself and when you wish to jump to the page that is linked, we select the hotspot or anchor. This technique is called
(a) Hypertext
(b) Hypermedia
(c) both (a) & (b)
(d) Anchoring

Q8. Which of the following is not a form of main memory?
(a) Instruction opcode
(b) Instruction register
(c) Instruction cache
(d) Translation look-aside buffer

Q9. The number of the edges in a regular graph of degree ‘d’ and ‘n’ vertices is
(a) Maximum of n, d
(b) n + d
(c) nd
(d) nd/2

Q10. Synthesized attribute can easily be simulated by an
(a) LL grammar
(b) ambiguous grammar
(c) LR grammar
(d) None of the above

 

 

SOLUTIONS

S1. Ans.(c)
Sol. A class member which is declared protected from before becomes the Private member of subclass.

S2. Ans.(a)
Sol. For n-bit adder, we require-
(a) (n-1) FA and 1 HA ; or
(b) n FA ; or
(c) (2n-1) HA & (n-1) OR gate.

S3. Ans.(d)
Sol.
(a) In Pre-order , the Root node is visited first, then the Left subtree and at last Right Subtree.
(b) In-order, Left Subtree is visited first , then the Root node, and at last Right Subtree.
(c) Post-order, at first Left Subtree, then Right Subtree and finally Root node.
(d) Level-order is breadth first traversal for the tree.

S4. Ans.(b)
Sol. Positive AND gate has input A, B and output AB.
Negative OR gate will have inverter at both inputs and 1 Output.
So, Output at the negative OR gate is
(A ̅+B ̅ ) ̅ = (AB) ̅ ̅ = AB = Positive AND gate output

S5. Ans.(a)
Sol. By principle of inclusion and exclusion, we get
P(AUB) = P(A) + P(B) + P(A∩B)
In Mutually exclusive condition –
P(A∩B) = 0

So, P(AUB) = P(A) + P(B)

S6. Ans.(b)

immediately be granted

S7. Ans.(c)

Sol. Both (a) and (b)

S8. Ans.(a)
Sol. Instruction opcode tells about what operation to be performed. Excluding it, all are form of a main memory.

S9. Ans.(d)
Sol. Given:
Number of vertices = n
Degree of each vertices or number of neighbours of each vertices = d
So, Total edges = nd/2

S10. Ans.(c)
Sol. Both Synthesized attribute and LR grammar are evaluated in bottom up method. So, these can be simulated easily.

Quiz: Mechanical Engineering 2 June 2020

Quiz: Mechanical Engineering
Exam: ISRO
Topic: Material science

Each question carries 1 mark
Negative marking: 1/3 mark
Time: 10 Minutes
Q1. Atoms are arranged in face centred cubic (FCC) structure as
(a) All eight corners of the cube
(b) All eight corners of the cube and one of the body center
(c) All eight corners of the cube and at the center of each face
(d) All eight corners of the cube and one at the body center with one at the center of each face

Q2. Which of the following are zero dimensional defects?
1. Vacancy
2. Interstitial defect
3. Substitutional defect
(a) 1 and 2 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3

Q3. The number of electrons found in the outer most orbit of semi-conductor materials is,
(a) 2
(b) 4
(c) 6
(d) 8

Q4. What is the packing factor of FCC crystal structure?
(a) 0.64
(b) 0.68
(c) 0.74
(d) 0.78

Q5. Which is false statement about annealing?
(a) Annealing is done to relieve stresses
(b) Annealing is done to harden steel slightly
(c) Annealing is done to improve machine characteristics
(d) Annealing is done to soften material

Q6. Pearlite is a combination of:
(a) Ferrite and cementite
(b) Cementite and gamma iron
(c) Ferrite and austenite
(d) Ferrite and iron graphite

Q7. The Burger’s vector lies parallel to the dislocation line along the axis of a line of atoms in the same plane in:
(a) Screw dislocation
(b) Edge dislocation
(c) Cracks
(d) Vacancies

Q8. The atomic bond found in diamond is:
(a) Ionic
(b) Covalent
(c) Metallic bond
(d) None of these

Q9. Carbon content is highest in:
(a) Mild steel
(b) Eutectoid steels
(c) Hypoeutectoid steels
(d) Hypereutectoid steels

Q10. Which of the following is non-destructive test
(a) tensile test
(b) charpy test
(c) cupping test
(d) radiography test

S1. Ans(c)
Sol. Atoms are arranged in face centred cubic structure as all eight corners of the cube and at the centre of each face.

S2. Ans(d)
Sol. Defects in metal
(1) Point defect or zero dimensional defect
(a) Vacancy defect
(b) Interstitial defect
(c) Substitutional defect
(d) Frankle defect
(e) Schottky defect
(2) Surface defect
(a) Grain boundary defect
(b) Twin boundary defect
(c) Tilt boundary defect
(d) Staking faults
(3) Line defect
(a) Edge dislocation defect
(b) Screw dislocation defect

S3. Ans(b)
Sol. The number of electrons found in the outer most orbit of semi-conductor materials is 4.

S4. Ans(c)
Sol. Type of cell Packing factor
Simple cubic (SC) – 0.52
Hexagonal Close packed (HCP) – 0.74
Body centered cubic (BCC) – 0.68
Face-centered cubic (FCC) – 0.74

S5. Ans(b)
Sol. Annealing reduces the hardness of the steel completely and improve toughness, it is complete softening process and increase ductility.

S6. Ans(a)
Sol. Pearlite consists of 87% ferrite (layer are thick) and 13% cementite (thin layer) arranged alternatively in a lamelle formation.

S7. Ans(a)
Sol. Screw dislocation:- When a part of Crystal displaced angularly over the remaining about some edge, the dislocation is called screw dislocation.
(i) Burger’s vector is parallel to the screw dislocation line, whose direction is perpendicular.
(ii) Screw dislocation creates shear stress and strain in the crystal.

S8. Ans(b)
Sol. The atomic bond found is diamond is covalent bond.
Covalent Bond:- It is also called homopolar bond. This bond result by mutual sharing of valence electrons of identical atoms. The electronic structure of an atom is relatively stable it has eight electrons in its outer valence shell, which sometimes an atom acquires by shearing electrons with an adjacent similar atom. Diamond, methane chlorine are typical examples.

S9. Ans(d)
Sol. Carbon content is highest in hypereutectoid steels.

S10. Ans(d)
Sol. radiography test is the non-destructive test. In the radiography test there is no role of force so there is no deformation takes place within the testing material.
After the testing material is able to perform its functionality without any kind of destruction.

Quiz: Electrical Engineering 1 June 2020

Quiz: Electrical Engineering
Exam: UPSSSC JE
Topic: Measurement and measuring instrument
Each question carries 1 mark.
Negative marking: 1/4 mark
Time: 10 Minute

Q1. Horizontally mounted moving iron instruments employ
(a) eddy current damping
(b) air friction damping
(c) fluid friction damping
(d) electromagnetic damping

Q2. The deflecting torque of moving iron instrument is
(a) I^2 dL/dθ
(b) 1/2 I^2 dL/dθ
(c) I dL/dθ
(d) 1/2 I dL/dθ

Q3. Hysteresis error, in moving iron instruments, may be reduced by using
(a) mumetal or permalloy
(b) stainless steel
(c) silver coating
(d) high speed steel

Q4. A spring controlled moving iron voltmeter draws a current of 1 mA for full scale value of 100 V. If it draws a current of 0.5 mA the meter reading is
(a) 25 V
(b) 50 V
(c) 100 V
(d) 200 V

Q5. Moving coil permanent magnet instrument can be used for the measurement of
(a) AC and DC
(b) AC only
(c) DC only
(d) half wave rectified DC

Q6. An advantage of PMMC instrument is that it
(a) is free from friction error
(b) has high torque to weight ratio of moving parts
(c) has low torque to weight ratio
(d) can be used on both AC and DC

Q7. The term artificial aging in instrument is associated with
(a) springs
(b) permanent magnets
(c) controlling torques
(d) both (a) and (b)

Q8. A PMMC voltmeter is connected across a series combination of a dc voltage source V1 = 2V and an ac voltage source V2(t)= 3 Sin (4t) volts. The meter reads
(a) 2 V
(b) 5 V
(c) (2+√3/2)V
(d) √17/2 V

Q9. Which of the following meters does not exhibit square law response?
(a) Moving coil
(b) Moving iron
(c) Electrodynamometer
(d) hot wire instrument

Q10. Which of the following instrument is commonly used to measure primary current of a transformer connected to mains?
(a) Electrostatic meter
(b) Current transformer
(c) Moving coil type meter
(d) Moving iron meter

Solutions
S1. Ans. (b)
Sol. air friction damping

S2. Ans. (b)
Sol. The correct relation for torque in moving iron is 1/2 I^2 dL/dθ.

S3. Ans. (a)
Sol. mumetal or permalloy

S4. Ans. (a)
Sol. Deflection, θ∝I^2
So, V∝I^2
V2 = V1 ((I^2 2)/(I^2 1)), putting the value in equation we get as the result
V2 = 25 V
S5. Ans. (c)
Sol. Moving coil permanent magnet instrument can be used for the measurement of DC only.

S6. Ans. (b)
Sol. has high torque to weight ratio of moving parts.

S7. Ans. (d)
Sol. Both spring and controlling torque are associated with term aging.

S8. Ans. (a)
Sol. The average value of ac current is zero so the instrument will measure 2 V .

S9. Ans. (a)
Sol. Moving iron

S10. Ans. (d)
Sol. Moving iron meter

Quiz: Civil Engineering 30 MAY 2020

Quiz: Civil Engineering
Exam: UPSSSC-JE
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes

Q1. According to IS 1200, the formwork shall be measured in:
(a) Tonnage
(b) cubic m
(c) square meter
(d) Linear length

Q2. The linear relation between the stress and strain of a material is valid until
(a) fracture stress
(b) elastic limit
(c) ultimate stress
(d) proportional limit

Q3. Water cement ratio is usually expressed in:
(a) Litres of water required per bag of cement
(b) Litres of water required per kg of cement
(c) m³ of water required per bag of cement
(d) m³ of water required per kg of cement

Q4. In a closed traverse……………..
(a) Difference between fore-bearing and back-bearing should be 90°
(b) Sum of included angles should be (2N-4) times right angle, where N represents the number of sides
(c) Sum of included angle should be (2N-1) time right angle, where N is the number of sides
(d) None of these

Q5. Minimum grade of concrete to be used in reinforced concrete is –
(a) M 10
(b) M 15
(c) M 20
(d) M25

Q6. Relative density of a compacted dense sand is approximately equal to
(a) 0.4
(b) 0.6
(c) 0.95
(d) 1.20

Q7. As per I.R.C. for bitumen bound macadam maximum aggregate impact value in % will be:
(a) 35
(b) 20
(c) 30
(d) 25

Q8. Aerobic attached growth process is classified under:
(a) activated sludge process
(b) chemical clarification
(c) biological treatment
(d) preliminary treatment

Q9. Dicken’s formula for determining maximum flood (with usual notation), is
(a) Q_p=CA^(3/4)
(b) Q_p=C_1 A^(2/3)
(c) Q_p=C√A
(d) Q_p=177C√A

Q10. Property of a fluid by which molecules of different kind of fluids are attracted to each other is called _________.
(a) adhesion
(b) cohesion
(c) viscosity
(d) compressibility

SOLUTIONS

S1. Ans.(c)
Sol. the formwork shall be measured in square meter.

S2. Ans.(d)
Sol. According to hooks law strain is directly proportional to stress within proportional limit.

S3. Ans.(a)
Sol. Water Cement ratio is usually expressed in liters of water required per bag of cement.
▭(water-cement ratio= (weight of water)/(weight of cement))

S4. Ans.(b)
Sol. In closed traverse, the sum of included angle should be (2n-4)×90°.
n→ No. of sides.

S5. Ans.(c)
Sol. ⇒ for Reinforced cement concrete minimum grade is M20
⇒ For plane cement concrete minimum grade is M15

S6. Ans.(c)
Sol. relative density of compacted dense sand equal to 0.95.

S7. Ans.(c)
Sol. As per I.R.C for bitumen bound macadam maximum aggregate impact value will be 30%.

S8. Ans.(c)
Sol. Aerobic attached growth process is a biological treatment in which biomass is attached over the medium and waste water passed through it.

S9. Ans.(a)
Sol. Peak flood discharge given by dicken’s formula-
Q=CA^(3/4)
Where Q= Peak flood discharge (m³/sec)
C= Dicken’s coefficient
A= Area in km²

S10. Ans.(a)
Sol. It is defined as-
Cohesion – an attractive force between same kind of fluid molecules.
Adhesion – an attractive force between different kind of fluid molecules.

Quiz: Mechanical Engineering 26 May 2020

Quiz: Mechanical Engineering
Exam: ISRO TECHNICAL ASSISTANT
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/3 mark
Time: 10 Minutes

Q1. Autofrettage is a method of
(a) joining thick cylinders
(b) Reliving stresses from thick cylinders
(c) Prestressing thick cylinders
(d) Increasing the life of thick cylinders

Q2. In circular arc cam with a flat faced reciprocating follower, the contact between the
follower and the nose of cam is only maintained if :
(a) External spring force is less than the inertia force of the follower
(b) External spring force is greater than the inertia force of the follower
(c) External spring force is zero
(d) The inertia force is more than the spring force

Q3. A governor is said to be isochronous when the equilibrium speed is
(a) variable for different radii of rotation of governor balls
(b) constant for all radii of rotation of the balls within the working range
(c) constant for particular radii of rotation of governor balls
(d) constant for only one radius of rotation of governor balls

Q4. The effect of increasing the stiffness of springs of centrifugal clutch is
(a) The decrease of engagement speed
(b) The increase of engagement speed
(c) The increase of frictional force at maximum speed
(d) None of the above

Q5. The saturation temperature of steam with increase in pressure increase
(a) linearly
(b) rapidly first and then slowly
(c) slowly first and then rapidly
(d) inversely

Q6. Carbonization of coal is the process of
(a) pulverizing coal in inert atmosphere
(b) heating wood in a limited supply of air at temperatures below 300°C
(c) strongly heating coal continuously for about 48 hours in the absence of air in a
closed vessel
(d) binding the pulverized coal into brackets

Q7. Superheating of steam is done at
(a) constant volume
(b) constant temperature
(c) constant pressure
(d) constant entropy

Q8. Fluid is a substance that
(a) cannot be subjected to shear forces
(b) always expands until it fills any container
(c) has the same shear stress at a point regardless of its motion
(d) cannot remain at rest under action of any shear force.

Q9. Match List-I with List-II and select the correct answer using the code given below the lists:
List – I
Heat exchangers
Turbulent flow
Free convection
Radiation heat transfer
List–II
View factor
Effectiveness
Nusselt number
Eddy diffusivity
Codes
A B C D
(a) 3 1 2 4
(b) 2 4 3 1
(c) 3 4 2 1
(d) 2 1 3 4

Q10. Specific speed of a fluid machine
(a) refers to the speed of a machine of unit dimensions
(b) is a type-number representative of its performance
(c) is specific to the particular machine
(d) depends only upon the head under which the machine operates

SOLUTIONS

S1. Ans.(c)
Sol. Autofrettage: It is one of the oldest methods of prestressing (method of increasing pressure capacity) the cylinders. It is overloading the cylinder before it is put into service. In this method, a forged cylinder is subjected to a large internal pressure, so as to expand the internal diameter, causing overstrain. The internal pressure is applied is such a way that a portion of the cylinder at the inner surface is subjected to stresses in the plastic range. When the pressure is released, the portion of the cylinder at the outer surface contracts exerting the pressure on the portion at the inner surface which has undergone permanent deformation. As a result residual compressive stresses are induced at the inner surface and tensile stresses at the outer surface.
It is commonly used to gun barrels. It not only increases the pressure capacity of the cylinder, but also improves the endurance strength.

S2. Ans.(b)
Sol. When the cam contact force goes to zero, the cam and follower will separate. Large enough spring force is necessary to keep cam and follower in contact throughout the entire rotation. External spring force should be greater than inertia force of the follower to maintain positive contact. If external spring force is too large, there is possibility of higher contact stress leading to surface failure.

S3. Ans.(b)
Sol. Isochronous governor is a governor that keeps the speed of a prime mover constant at all loads. Also known as a static governor. A governor is said to be isochronous if equilibrium speed is constant for all the radii of rotation in the working range. Therefore, for an isochronous governor the speed range is zero and this type of governor shall maintain constant speed.

S4. Ans.(b)
Sol. When the load is released from clutch lever, it again engages with the shaft. As the stiffness of spring will increases, the restoring force on clutch will increase and hence velocity of engagement will be more.

S5. Ans (b)
Sol. At atmospheric pressure the saturation temperature is 100°C. However, if the pressure is increased, this will allow the addition of more heat and an increase in temperature without a change of phase. Therefore, increasing the pressure effectively increases both the enthalpy of water, and the saturation temperature.

S6. Ans (c)
Sol. Coal carbonization is used for processing of coal to produce coke using metallurgical grade coal. Coal carbonization involves heating of coal in the absence of air.

S7. Ans (c)
Sol. Superheated steam is a steam at a temperature higher than its vaporization (boiling) point at the absolute pressure where the temperature is measured

S8. Ans (d)
Sol. A fluid is a substance that continuously deforms under an applied shear force.

S9. Ans.(b)
Sol.
(a) Heat exchangers : Effectiveness
(b) Turbulent flow : Eddy diffusivity
(c) Free convection : Nusselt number
(d) Radiation heat transfer : View factor

S10. Ans (b)
Sol. Specific speed is of a fluid machine is a type number representative of its performance.
In order to compare the performance of different pumps, it is necessary to have some term which will be common to all the centrifugal pump the term ordinarily used for this purpose is the specific speed. This is a type characteristic and can be used to predict the behavior of one pump based on tests of similar, but different sized pumps.
The specific speed is a characteristic of pumps which can be used as basis for comparison of the performance of different pump.

Quiz: Mechanical Engineering 22 May 2020

Quiz: Mechanical Engineering
Exam: NLC GET
Topic: Miscellaneous
Each question carries 1 mark
Negative marking: 1/3 mark
Time: 10 Minutes

Q1. The maximum force which acts on the connecting rod is
(a) Force due to gas pressure
(b) Force due to inertia of piston
(c) Force due to friction of connecting rod
(d) Force due to crank pin

Q2. Strain rosettes are generally used for
(a) measurement of load
(b) measurement of shear strain
(c) measurement of longitudinal strain
(d) measurement of resilience

Q3. Toggle mechanism have following applications except
(a) Stone crushers
(b) Gear cutting
(c) Embossing presses
(d) Switches

Q4. Match the following List-I and List-II and select the correct answer using the codes
given below the lists:
List-I
A. Pantograph
B. Single slider crank chain
C. Double slider crank chain
D. Straight line motion
List-II
1. Scotch yoke mechanism
2. Double lever mechanism
3. Tchebicheff mechanism
4. Double crank mechanism
5. Hand pump
Codes:
A B C D
(a) 4 3 5 1
(b) 2 5 1 3
(c) 2 1 5 3
(d) 4 5 2 1

Q5. The delay period in CI engine depends upon
1. Temperature and pressure in the cylinder at the time of injection
2. Strength of fuel mixture
3. Relative velocity between the fuel injection and air turbulence pressure of residual gas
4. Engine output
Select the correct answer:
(a) 1, 2, 3 and 4
(b) 1, 2 and 3
(c) 1, 2 and 4
(d) 1, 3 and 4

Q6. At breakeven point:
(a) Sales revenue > total cost
(b) Sales revenue = total cost
(c) Sales revenue < total cost
(d) None of the above

Q7. In which of the following process, a small-diameter thick ring is expanded into a large diameter thinner ring by placing the ring between two rolls
(a) Shape rolling
(b) Tube rolling
(c) Ring rolling
(d) Continuous rolling

Q8. The instrument preferred in the measurement of highly fluctuating velocities in air flows is
(a) Pitot-static tube
(b) Propeller type anemometer
(c) Three cup anemometer
(d) Hot wire anemometer

Q9. A metal block is thrown into deep lake. As it sinks deeper in water, the buoyant force acting on it
(a) increases
(b) remains the same
(c) decreases
(d) first increases and then decreases

Q10. Match the following List-I with List-II and select the correct answer using the codes given below
List-I
A. Rigid coupling
B. Oldham’s coupling
C. Universal joint
D. Gear coupling
List-II
1. Permits greater torque capacity for a given size
2. Permits substantial angular misalignment of intersecting axes
3. Permits substantial lateral offset and little angular alignment
4. Permits almost no misalignment
Codes:
A B C D
(a) 1 2 3 4
(b) 4 2 3 1
(c) 1 3 2 4
(d) 4 3 2 1

 

SOLUTIONS

S1. Ans (a)
Sol. All of the given forces act on the connecting rod but the major force that acts on the connecting rod is the force due to gas pressure.

S2. Ans(c)
Sol. strain rosettes are generally used for measurement of longitudinal strain.
A strain gauge rosette is a term for an arrangement of two or more strain gauges that are positioned closely to measure strains along different directions of the component under evaluation. Single strain gauges can only measure strain effectively in one direction, so the use of multiple strain gauges enables more measurements to be taken, providing a more precise evaluation of strain on the surface being measured.

S3. Ans (b)
Sol. Stone crushers, embossing presses and switches works on toggle mechanism. Mechanical advantage of toggle mechanism is infinite or very large.

S4. Ans (b)
Sol. Pantograph utilizes double lever mechanism, Hand pump utilizes single slider crank chain, Scotch-yoke mechanism is an inversion of double slider crank chain and Tchebicheff mechanism is an approximate straight-line motion mechanism.

S5. Ans (a)
Sol. Following factors affects the delay period in CI engine
1. Temperature and pressure in cylinder
2. Engine output
3. Relative velocity of fuel injection and air turbulence
4. Strength of fuel mixture
5. Compression ratio

S6. Ans(b)
Sol. Breakeven point- The breakeven point is the level of production at which the costs of production equal the revenues for a product. At breakeven point, profit will be zero even there is no loss.
Which means sales revenue is equal to total cost.
Sales revenue = total cost

S7. Ans.(c)
Sol. Ring rolling is an operation of metal forming in which a small diameter, thick ring is
converted into large diameter, thinner ring by placing the ring between two rolls.

S8. Ans (d)
Sol. Hot wire anemometer is used for the measurement of highly fluctuating velocities in air. This can be done by measuring the heat loss of the wire which is placed in the fluid stream. The wire is heated by electrical current. The hot wire when placed in the stream of the fluid, in that case, the heat is transferred from wire to fluid, and hence the temperature of wire reduces. The resistance of wire measures the flow rate of the fluid which is the function of heat loss from the wire and change in the resistance of wire.

S9. Ans (b)
Sol. As buoyant force depends only on the displaced volume of fluid by the submerged or floating body according to Archimedes principle. So, volume displaced by the metal block will remain constant from when it sinks in the fluid till it sinks deeper, hence, the buoyant force on the metal block remains same.

S10. Ans (d)
Sol.
• Rigid coupling permits almost no misalignment.
• Oldham’s coupling permits substantial lateral offset and little angular alignment.
• Universal joint permits substantial angular misalignment of intersecting axes.
• Gear coupling permits greater torque capacity for a given size.

Quiz: Electrical Engineering 21 May 2020

Quiz: Electrical Engineering
Exam: UPPSC AE
Topic: Analog and digital electronics (electrical engineering)

Each question carries 1 mark.
Negative marking: 1/4 mark
Time: 10 Minute

Q1. A FET transistor with an antiparallel body diode block:
(a) Bidirectional voltage and passes unidirectional current
(b) Bidirectional voltage and passes bidirectional current
(c) Unidirectional voltage and passes unidirectional current
(d) Unidirectional voltage and passes bidirectional current

 

Q2. Turn-on of a Thyristor takes place when
(a) anode to cathode voltage is positive
(b) anode to cathode voltage is negative
(c) there is a positive current pulse at the gate
(d) the anode to cathode voltage is positive and there is a positive current pulse at the gate

 

Q3. After firing an SCR, the gate pulse is removed. The current in the SCR will
(a) remain the same
(b) immediately fall to zero
(c) rise up
(d) rise a little and then fall to zero

 

Q4. When a thyristor is in ON state, its gate drive be
(a) removed to save power
(b) removed or may not be removed
(c) not removed as it will turn off the thyristor
(d) removed to avoid increased losses and higher junction temperature

 

Q5. Current in SCR to turn on transient can be reduced by
(a) connecting a small inductor in series with the anode
(b) connecting a small inductor in parallel with the anode
(c) connecting a small capacitor in series with the anode
(d) connecting a small capacitor in parallel with the anode

 

Q6. Which of following does not cause damage of an SCR?
(a) high current
(b) high rate of rise of current
(c) high temperature rise
(d) high rate of rise of voltage

 

Q7. When compared to those of a symmetrical thyristor, the turn off time and reverse blocking voltage of an asymmetrical thyristor are respectively
(a) large and large
(b) large and small
(c) small and large
(d)small and small

 

Q8. The duration of reverse recovery transient affects the following aspect in a power diode
(a) peak inverse voltage
(b) forward threshold voltage
(c) speed of response
(d) average current

 

Q9. Surge current rating of an SCR specifies the maximum
(a) repetitive current with rectangular wave
(b) non- repetitive current with sine wave
(c) non- repetitive current with rectangular wave
(d) repetitive current with sine wave

 

Q10. The dv/dt effect in SCR can result in
(a) Low capacitive charging current
(b) false triggering
(c) increased junction capacitance
(d) high rate of rise of anode voltage

 

Solutions
S1. Ans. (d)
Sol. Unidirectional voltage and passes bidirectional current

 

S2. Ans. (d)
Sol. the anode to cathode voltage is positive and there is a positive current pulse at the gate.

 

S3. Ans. (a)
Sol. remain the same

 

S4. Ans. (d)
Sol. removed to avoid increased losses and higher junction temperature

 

S5. Ans. (a)
Sol. connecting a small inductor in series with the anode

 

S6. Ans. (d)
Sol. high rate of rise of voltage

 

S7. Ans. (d)
Sol. Both quantities need to be small.

 

S8. Ans. (a)
Sol. The duration of reverse recovery transient affects the following aspect in a power diode peak inverse voltage.

 

S9. Ans. (b)
Sol. non- repetitive current with sine wave

 

S10. Ans. (b)
Sol. false triggering

Quiz: Mechanical Engineering 21 May 2020

Quiz: Mechanical Engineering
Exam: UPPSC AE
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/3 mark
Time: 10 Minutes

Q1. In offset slider crank mechanism, the ratio of the working stroke time to the return
stroke time is
(a) less than 1
(b) equal to 1
(c) more than 1
(d) no specific range or value

Q2. Match List-I with List-II and select the correct answer using the given lists:
List-I
A. Compound train
B. Quick return mechanism
C. Exact straight-line motion
D. Approximate straight-line motion
List-II
a. Hart mechanism
b. Coriolli’s force
c. Transmission of motion around bends and corners
d. Watt mechanism

(a) A – a, B – b, C – c, D – d
(b) A – c, B – b, C – a, D – d
(c) A – c, B – d, C – a, D – b
(d) A – a B – d, C – c, D- b

Q3. A system and its environment put together constitute
(a) an adiabatic system
(b) an isolated system
(c) a segregated system
(d) a homogenous system

Q4. For a system to be in thermodynamic equilibrium the system and its surroundings
are to be in
(a) Thermal equilibrium
(b) Chemical equilibrium
(c) Mechanical equilibrium
(d) Thermal, chemical and mechanical equilibrium

Q5. In a centrifugal compressor, an increase in speed at a given pressure ratio causes.
(a) increase in flow and increase in efficiency
(b) increase in flow and decrease in efficiency
(c) Decrease in flow and decrease in efficiency
(d) decrease in flow and increase in efficiency

Q6. Consider the following statements about true-stress-strain method:
1. It is more sensitive to changes in both metallurgical and mechanical conditions.
2. It gives a more accurate picture of the ductility.
3. It can be correlated with stress-strain values in other tests like torsion, impact,
combined stress tests etc.
4. It can be used for compression tests as well.
Which of the above statements are correct?
(a) 1,2 and 3
(b) 1,3 and 4
(c) 2,3 and 4
(d) All of the above

Q7. Detonation in the SI engine becomes severe during
(a) Low load and high speed
(b) High load and high speed
(c) Low load and low speed
(d) High load and low speed

Q8. The static friction
(a) bears a constant ratio to the normal reaction between the two surfaces
(b) is independent of the area of contact, between the two surfaces
(c) always acts in a direction, opposite to that in which the body tends to move
(d) all of the above

Q9. What happens to the specific volume of water when it is heated at 0°C?
(a) Decreases steadily
(b) Increases steadily
(c) first increases then decreases
(d) First decreases then increases

Q10. The Porter governor is an example of…………
(a) Inertia governor
(b) Flywheel governor
(c) Centrifugal governor
(d) None of these

SOLUTIONS
S1. Ans.(c)
Sol. A slider crank mechanism is a quick-return motion mechanism. In which return stroke
time is less than the forward stroke time

S2. Ans.(b)
Sol. Hart mechanism is an exact straight-line mechanism.
Quick return motion mechanism has one link (slider) translating on another rotating link. Which causes Coriolis acceleration in slider.

S3. Ans (b)
Sol. A system and its surrounding constitute a universe which is an isolated system.

S4. Ans (d)
Sol. A thermodynamic system will be in thermodynamic equilibrium with its surrounding when it is in thermal equilibrium (temperature is equal to surrounding), chemical equilibrium (chemical potential of system with respect to surrounding is zero) and mechanical equilibrium (Pressure of system is equal to that of surrounding) simultaneously.

S5. Ans.(b)
Sol. By increase in speed at a given pressure ratio, mass flow rate increases but-efficiency decreases due to various frictional losses.

S6. Ans (d)
Sol.
True stress-strain curve is more sensitive to changes in both metallurgical and mechanical conditions, it can give a more accurate picture of the ductility and can be correlated with stress-strain values in other tests like torsion, impact, combined stress tests etc.

S7. Ans (d)
Sol. Detonation in SI engine will become severe at high load and low speed because at higher loads, the temperature of cylinder and combustion chamber walls will be higher and hence temperature of the end charge will be more which increases knocking tendency in SI engine and at lower engine speed, longer will be the absolute time for the flame to traverse the cylinder which increases the time available for pre flame reactions hence the tendency to knock increases.

S8. Ans.(d)
Sol. In case of static friction it is the ratio of Normal reaction between the surface to the friction force.
It is always opposing the motion or tending to motion of the body so always act in opposite direction.

S9. Ans.(d)
Sol. As, density of water is maximum at 4°C so when temperature of water is increased then upto 4°C specific volume decreases due to density increase and after that specific volume increase.

S10. Ans.(c)
Sol. Types of centrifugal governor.
(1) Watt governor
(2) Porter governor
(3) Proell governor
(4) Hartnell governor
In centrifugal governor, centrifugal force on balls will decide the sleeve movement and control the mean speed.

Quiz: Civil Engineering 19 may 2020

Quiz: Civil Engineering

Exam: Telangana PSCM

Topic: Miscellaneous

 

Each question carries 1 mark

Negative marking: No negative marking

Time: 10 Minutes

 

Q1. What is the ratio of weight of rail in tonnes to the locomotive axle load in tonnes in India?

(a) 1:510

(b) 1:410

(c) 1:310

(d) 1:210

 

Q2. The distemper is used to coat:

(a) External concrete surface

(b) interior surface not exposed to weather

(c) Woodwork

(d) Compound walls

 

Q3. Which term is appropriate for the branch of physical geography which deals with the origin, distribution of water on the earth surface?

(a) Hydrolysis

(b) Oxidation

(c) Hydropethia

(d) Hydrology

 

Q4. Torsion resisting capacity of a given reinforce concrete section…………

(a) Decreases with decrease in stirrup spacing

(b) Decreases with increase in longitudinal bars

(c) Does not depend upon stirrup and longitudinal steels

(d) Increases with the increases in stirrups and longitudinal

 

Q5. Reduction in volume of soil primarily due to squeezing out of water from the voids is called:

(a) Primary consolidation

(b) Plastic flow

(c) Creep

(d) Secondary consolidation

 

Q6. Principal planes are planes of

(a) maximum shearing stress

(b) zero shearing stress

(c) shearing stress having a magnitude of 50% of principal stress

(d) will be maximum

 

Q7. A surface tangential to the level surface at any point is known as:

(a) Datum surface

(b) Collimation surface

(c) Horizontal surface

(d) Mean sea level

 

Q8. What does Chemical Oxygen Demand (COD) indicate?

(a) Biodegradability of the waste water

(b) Potential for recycling the wastewater

(c) Age of the sewage

(d) Strength of a sewage

 

Q9. The unit weight of R. C. C. (in kg/m³)……..

(a) 1200

(b) 1800

(c) 2500

(d) 3000

 

Q10. Property of a fluid at zero temperature is referred to as _________.

(a) Stagnation property

(b) Standard property

(c) Simple property

(d) None of these

 

 

SOLUTION

 

S1. Ans.(a)

Sol. The ratio of weight of rail in tones to the locomotive axle load in tonnes is 1:510 in India.

 

S2. Ans.(b)

Sol. Distemper is used to coat interior surface not exposed to weather. It is made with base as white chalk and thinner as water.

 

S3. Ans.(d)

Sol. Hydrology is a branch of science which deals with circulation, distribution and movement of water on and below the earth surface and its atmosphere.

 

S4. Ans.(d)

Sol. Torsion resisting capacity of a given reinforced concrete section increase with increases in stirrups and longitudinal steel.

 

S5. Ans.(a)

Sol. primary consolidation – due to expulsion of pore water

Secondary consolidation – Due to plastic rearrangement of soil solid.

 

S6. Ans.(b)

Sol. Infinite planes passes through a single point. Out of infinite planes three planes are mutually perpendicular to each other and having zero shear stress, that planes are called principal plane.

 

S7. Ans.(c)

Sol. the surface parallel to earth surface in known as level surface and tangent to any point of level surface is horizontal surface.

 

S8. Ans.(a)

Sol. Chemical oxygen demand indication the amount of oxygen required to carry out the decomposition of both biodegradable or non-biodegradable organic matter present in the system.

 

S9. Ans.(c)

Sol. Unit weight of R.C.C. = 2500 kg/m³

Unit weight of plain cement concrete = 2400 kg/

 

S10. Ans.(a)

Sol. The property at which it’s all energy measured at its static condition. When a fluid having zero velocity then it is the condition of stagnation. then its K.E. is zero and K.E. is function of absolute temp. so at zero absolute temp. property of fluid is known as stagnation property.

 

 

 

 

 

 

 

 

 

Quiz: Mechanical Engineering 19 May 2020

Quiz: Mechanical Engineering
Exam: ISRO Technical Assistant
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/3 mark
Time: 10 Minutes

Q1. A closed thermodynamic system is one in which
(a) there is no energy or mass transfer across the boundary
(b) there is no mass transfer, but energy transfer exists
(c) there is no energy transfer, but mass transfer exists
(d) both energy and mass transfer take place across the boundary, but the mass
transfer is controlled by valves

Q2. Which one of the following thermodynamic processes approximates the steaming of food in a pressure cooker?
(a) isenthalpic
(b) isobaric
(c) isochoric
(d) isothermal

Q3. Specific speed of a fluid machine
(a) refers to the speed of a machine of unit dimensions
(b) is a type-number representative of its performance
(c) is specific to the particular machine
(d) depends only upon the head under which the machine operates

Q4. The component of torque converter that allows torque multiplication is
(a) Turbine
(b) Impeller
(c) Stator
(d) Freewheel

Q5. Increase in entropy of a system represents
(a) Increase in availability of energy
(b) Increase in temperature
(c) Decrease in pressure
(d) Degradation of energy

Q6. Priming is necessary in
(a) Centrifugal pumps to lift water from a greater depth
(b) centrifugal pumps to remove air in the suction pipe and casing
(c) Hydraulic turbine to remove air in the turbine casing
(d) Hydraulic turbine to increase the speed of turbine and to generate more power

Q7. Air at 35°C DBT and 25°C dew point temperature passes through the water shower whose temperature is maintained at 20°C. What is the process involved?
(a) cooling and humidification
(b) sensible cooling
(c) cooling and dehumidification
(d) heating and humidification

Q8. Piston compression rings are made of which one of the following?
(a) Cast iron
(b) Bronze
(c) Aluminium
(d) White metal

Q9. The Klein’s method of construction for reciprocating engine mechanism
(a) is based on acceleration diagram
(b) is a simplified from of instantaneous centre method
(c) utilizes a quadrilateral similar to the diagram of mechanism for reciprocating engine
(d) enables determination of Coriolis component

Q10. In resistance welding, voltage used for heating is
(a) 1 V
(b) 10 V
(c) 100 V
(d) 500 V

Solutions

S1. Ans.(b)
Sol. A closed system consists of fixed amount of mass and no mass can cross its boundary but energy in the form of heat and work can cross the boundary.

S2. Ans.(c)
Sol. Volume of pressure cooker is always constant hence it is isochoric process.

S3. Ans (b)
Sol. Specific speed is of a fluid machine is a type number representative of its performance.
In order to compare the performance of different pumps, it is necessary to have some term which will be common to all the centrifugal pump the term ordinarily used for this purpose is the specific speed. This is a type characteristic and can be used to predict the behaviour of one pump based on tests of similar, but different sized pumps.
The specific speed is a characteristic of pumps which can be used as basis for comparison of the performance of different pump.

S4. Ans (c)
Sol. A hydraulic torque converter consists of series of fixed guide vanes which are provided between turbine runner and pump impeller. The liquid exerts a torque on the driven unit through these stationary guide vanes as it flows from pump to turbine runner.

S5. Ans (d)
Sol. Entropy is the measure of degree of Randomness. Increase in entropy of a system represents degradation of energy.

S6. Ans.(b)
Sol. filling the pump casing and the suction pipe with the liquid before it is started is known as priming. Unless the centrifugal pump is primed, it will not start as there is no centrifugal head impressed on the liquid. Positive displacement type reciprocating or rotary pump do not need priming because the air, if any, in the cylinder or casing is driven out by the piston or vanes.

S7. Ans.(c)
Sol. As the temperature of water shower is less than dew point temperature hence, water vapour starts condensing. Thus, process involved is cooling and dehumidification.

S8. Ans.(a)
Sol. Since grey cast iron has properties of self-lubrication and damping of small Vibration they are widely used for machine base, engine frames, drainage pipes, elevator and industrial furnace counter weights, pump housings cylinder and piston rings of IC engines, flywheel etc.

S9. Ans (c)
Sol. In Klein’s Construction, the velocity and the acceleration diagrams are made on the configuration diagram itself. The line that represents the crank in the configuration diagram also represents the velocity and acceleration of its moving end in the velocity and acceleration diagram.

S10. Ans (b)
Sol. Resistance welding processes are pressure welding processes in which heavy current is passed for short time through the area of interface of metals to be joined. These processes differ from other welding processes in the respect that no fluxes are used, and filler metal rarely used. All resistance welding operations are automatic and, therefore, all process variables are presents and maintained constant. Heat is generated in localized area which is enough to heat the metal to sufficient temperature, so that the parts can be joined with the application of pressure. Pressure is applied through the electrodes.
The process employs currents of the order of few KA, voltages range from 2 to 12 volts and times vary from few milliseconds to few seconds.

Quiz: Mechanical Engineering 18 May 2020

Quiz: Mechanical Engineering
Exam: UPSSSC JE
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/3 mark
Time: 10 Minutes

Q1. Which one of the following statements is correct?
(a) A machine which violates Clausius statement will violate the first law of thermodynamics
(b) A machine which violates Kelvin-Plank statement will violate the first law of thermodynamics
(c) A machine which violates the second law of thermodynamics will violate the first law of thermodynamics
(d) A machine which violates Kelvin-Plank statement will violate the Clausius statement

Q2. The conditioned air supplied to the room must have the capacity to take up
(a) Room sensible heat load only
(b) Room latent heat load only
(c) Both room sensible heat load and room latent heat load
(d) Neither room sensible heat load nor room latent heat load

Q3. Consider the following statements:
1. In model testing, the same fluid must be used in prototype and also the model
2. Models should be smaller than prototype for geometric similarity
3. Geometrically similar boundaries do not necessarily imply kinematically homogeneous flows
4. Existence of geometric similarity does not imply dynamic similarity
Which of the above statements are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 3 and 4 only
(d) 1 and 4 only

Q4. The discharge through a converging-diverging nozzle reaches its maximum value when the flow becomes
(a) Sonic at the exit
(b) Sonic at the throat
(c) Supersonic at the throat
(d) Subsonic at the throat

Q5. ‘Shockless entry’ of water in hydraulic turbines is of much significance from the standpoint of
(a) Hydraulic efficiency
(b) Mechanical efficiency
(c) Both hydraulic efficiency and mechanical efficiency
(d) Neither hydraulic efficiency nor mechanical efficiency

Q6. In solving a lumped parameter problem, which one of the following pair of non-dimensional numbers is used?
(a) Grashoff number and Biot number
(b) Prandtl number and Nusselt number
(c) Biot number and Fourier number
(d) Fourier number and Reynolds number

Q7. Which one of the following key types is pressed against the shaft for power transmission by friction between the key and the shaft?
(a) Feather key
(b) Square key
(c) Flat key
(d) Saddle key

Q8. The difference between member of a truss and of a beam is:
(a) The members of a truss take their loads along their length whereas a beam takes loads at right angles to its length
(b) The member of the truss takes load lateral to its length whereas the beam along the length
(c) The member of the truss can be made of C.I whereas the beam is of structural steel only
(d) The member of the truss can have a circular cross-section whereas the beam can have any cross-section

Q9. For an Oldham coupling used between two shafts, which among the following statements are correct?
I. Torsional load is transferred along shaft axis.
II. A velocity ratio of 1:2 between shafts is obtained without using gears
III. Bending load is transferred transverse to shaft axis.
IV. Rotation is transferred along shaft axis.
(a) I and II
(b) I and IV
(c) II and III
(d) II and IV

Q10. The maximum theoretical work obtainable, when a system interacts to equilibrium with a reference environment, is called
(a) Entropy
(b) Enthalpy
(c) Exergy
(d) Rothalpy

SOLUTIONS

S1. Ans(d)
Sol. A machine which violates kelvin-plank statement will violate the Clausius statement because
Kelvin-plank states that it is impossible to construct a device which operates in a cycle with single fixed temperature heat reservoir while Clausius states that it is impossible to construct a device which transfer heat from a lower temperature reservoir to a high temperature reservoir without any kind of work input. These two statements are complimentary to each other.

S2. Ans(c)
Sol. The conditioned air supplied to the room must have the capacity to take up Both room sensible heat and latent heat loads.

S3. Ans(c)
Sol. following observations can be made-
(a) Existence of geometric similarity does not imply dynamic similarity.
(b) Geometrically similar boundaries do not necessarily imply kinematically homogeneous flows.

S4. Ans(b)
Sol. The discharge through a converging-diverging nozzle reaches its maximum value when the flow becomes Sonic at the throat for which Mach number value is 1.

S5. Ans(a)
Sol. ‘Shockless entry’ of water in hydraulic turbines is of much significance from the standpoint of Hydraulic efficiency.
The hydraulic efficiency of hydraulic turbine is very much affected by shock less entry. Shock less entry in turbine ensure that the power loss in the turbine is less.

S6. Ans(c)
Sol. In solving a lumped parameter problem, pair of non-dimensional number such as Biot number and Fourier number is used.
Significance of Biot Number-
(a) Biot Number tells us whether lumped heat analysis is applicable or not.
If Bi<0.1 only then lumped heat analysis is applicable
(b) As it is the ratio of conductive resistance to convective resistance, it signifies low conductive resistance and large convective resistance.
Significance of Fourier Number-
(a) It signifies degree of penetration of heating or cooling effect.
(b) It is a measure of heat conducted through a body relative to heat stored.

S7. Ans(d)
Sol. saddle key is used for power transmission by friction between the key and the shaft.
(a) saddle key – saddle key is the key which is fit into the keyway of the hub only and no keyway in the shaft. It is likely to slip round under the shaft under load.
(b) feather key – feather key is the parallel key which is faster to one part (hub/shaft) with the help of the screws.
(c) square key – square key is the key having square cross-section.
(d) flat key – flat key is a taper key having provision in the hub only and will be floated on the shaft and the shaft is hold by mean of friction.

S8. Ans(b)
Sol. The difference between member of a truss and of a beam is the member of the truss takes load lateral to its length whereas the beam along the length.
Truss- A truss is a structure that consists of members organised into connected triangles so that the overall assembly behaves as a single object. Trusses are most commonly used in bridges, roofs and towers. A truss is made up of a web of triangles joined together to enable the even distribution of weight and the handling of changing tension and compression without bending or shearing. The triangle is geometrically stable when compared to a four (or more) -sided shape which requires that the corner joints are fixed to prevent shearing.
Beam- A beam is a structural element that primarily resists loads applied laterally to the beam’s axis. Its mode of deflection is primarily by bending. The loads applied to the beam result in reaction forces at the beam’s support points. The total effect of all the forces acting on the beam is to produce shear forces and bending moments within the beam, that in turn induce internal stresses, strains and deflections of the beam. Beams are characterized by their manner of support, profile (shape of cross-section), equilibrium conditions, length, and their material.

S9. Ans(b)
Sol. Oldham’s coupling is used to transmit power between two shafts having small angular misalignment. There is no bending load or reduction/increase of speed criterion. Hence only I and IV statements are correct.

S10. Ans(c)
Sol. As per the definition of the Exergy (or) Available Energy, we know that the maximum portion of energy which could be converted into useful work by ideal processes which reduce the system to dead state is known as Exergy.

Quiz: Civil Engineering 15 may 2020

Quiz: Civil Engineering
Exam: UPSSSC-JE
Topic: Transportation Engineering

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes

Q1. The target of achieving an overall density of road length in third 20-year road Development Plan (1981-2001) was
(a) 32 km /100km²
(b) 45.7 km /100km²
(c) 82 km /100km²
(d) 100 km /100km²

Q2. For a comfortable travel on highways, the centrifugal ratio should not exceed …………….
(a) 0.1
(b) 0.2
(c) 0.25
(d) 0.15

Q3. The coefficient of lateral friction for equilibrium super elevation is taken
(a) 0.15
(b) 0.35
(c) 0.4
(d) 0

Q4. The ruling gradient for plain and rolling terrain is
(a) 3.3%
(b) 5%
(c) 6%
(d) 4 %

Q5. At sharp horizontal curve of highways of radius ‘R’ (in metres), the percentage reduction in gradient provided to compensate the loss of traction force due to curvature is:
(a) 50/R
(b) 75/R
(c) 100/R
(d) None of these

Q6. Annual average daily traffic is obtained by determining average daily traffic volume recorded for
(a) 302 days
(b) 365 days
(c) 24 months
(d) 10 years

Q7. The travel time per unit length of road is __________ proportional to the speed.
(a) Cubically
(b) Directly
(c) Logarithmically
(d) Inversely

Q8. California bearing ratio (CBR)
(a) is a measure of soil strength
(b) is a procedure for designing flexible pavements
(c) is a method of soil identification
(d) is a measure to indicate the relative strength of paving materials

Q9. The height of the dowel above the road level should not be more than:
(a) 10 cm
(b) 20 cm
(c) 30 cm
(d) 40 cm

Q10. The ductility of bitumen is expressed as
(a) time
(b) Distance
(c) Speed
(d) None

SOLUTION

S1. Ans.(c)
Sol. (a) In first 20-year road plan (1943-1963), road density is 16 km/100 km².
(b) In second 20-year road plan (1961-1981) road density is 32 km/100 km².
(c) In third 20-year road plan (1981-2001) road density is 82 km/100 km².

S2. Ans.(c)
Sol. for a comfortable travel on highway, the centrifugal ratio should not exceed 0.25 and for railways, it should not exceed 0.125.

S3. Ans.(a)
Sol. The coefficient of lateral friction for equilibrium super elevation is taken as 0.15.

S4. Ans.(a)
Sol. The ruling gradient for plain and rolling terrain is 3.3% or 1 in 30 while for mountainous terrain it is 5% or 1 in 20.

S5. Ans.(b)
Sol. At sharp horizontal curve of highways of radius ‘R’, the percentage reduction in gradient provided to compensate the loss of traction force due to curvature is 75/R. Grade compensation is applicable for horizontal curve with gradient.

S6. Ans.(b)
Sol. Annual average daily traffic is obtained by determining average daily traffic volume recorded for 365 days and it is given by –

▭(AADT=(Total number of vehicle passing across a section in a year )/365)

S7. Ans.(d)
Sol. The travel time per unit length of road is inversely proportional to the speed.
▭(dt α 1/V )

S8. Ans.(a)
Sol. California Bearing ratio (CBR) is a measure of arbitrary soil strength. IRC consider CBR method for designing of flexible pavement.

S9. Ans.(c)
Sol. Dowel bare are used in expansion joints. The height of the dowel above the rood level should not be more than 30cm.

S10. Ans.(b)
Sol. The ductility of bitumen is expressed as distance. The minimum ductility value of bitumen according to IRC is 75 cm.