Quiz: Mechanical Engineering:Miscellaneous

Quiz: Mechanical Engineering

Exam: NLC (GET)

Topic: Miscellaneous

 

Each question carries 1 mark.

Negative marking: 1/4 mark

Time: 10 Minute

 

Q1.    Reversible adiabatic process is also called

(a) Isothermal process

(b) Isochoric process

(c) Isentropic process

(d) none of these

 

L1Difficulty 3
QTags Mechanical
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Q2.    Stirling Cycle consists of

(a) Two isochoric process and two isobars

(b) Two isothermal process and two isobars

(c) Two isochoric process and two isothermal process

(d) Two isochoric process and two isentropic process

 

L1Difficulty 3

QTags Mechanical

QCereator Paper Maker 10

Q3.  Prandtl number is

(a) 〖(Hydrodynamic boundary layer / thermal boundary layer)〗^3
(b) 〖(Thermal boundary layer /Hydrodynamic boundary layer)〗^3

(c) Thermal conductivity /electrical conductivity

(d) None of these

 

L1Difficulty 3

QTags Mechanical

QCereator Paper Maker 10

Q4.  Photochemical smog is mainly due to

(a)        and HC

(b)       CO and

(c)       Excess

(d)       Soot and PM

 

L1Difficulty 3

QTags Mechanical

QCereator Paper Maker 10

 

 

Q5.  When a boat enters river from a sea, one can expect

(a) to rise a little

(b) to fall a little

(c) to remain at same level

(d) depends upon boat density

 

L1Difficulty 3

QTags Mechanical

QCereator Paper Maker 10

Q6. In a two-dimensional problem, the state of pure shear at a point is characterized by

(a) ϵx=ϵy and γxy=0
(b) ϵx=2ϵy and γxy≠0
(c) ϵx=ϵy and γxy≠0
(d) ϵx= 0.5ϵy and γxy=0

L1Difficulty 3

QTags Mechanical

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Q7. Euler’s formula holds good only for

(a) Short column

(b) Both short and long column

(c) Weak column

(d) Long column

 

L1Difficulty 3

QTags Mechanical

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Q8. If velocity reduction ratio is above 100 then we use

(a) Spur gear

(b) Worm and worm gear

(c) Helical gear

(d) Bevel gear

 

L1Difficulty 3

QTags Mechanical

QCereator Paper Maker 10

Q9. Following gases are used in TIG welding

(a) Argon and helium

(b)  and

(c) Argon and Neon

(d) Helium and Neon

 

L1Difficulty 3

QTags Mechanical

QCereator Paper Maker 10

Q10.Most commonly used material, casted by cold chamber die casting

(a) Lead

(b) Zinc

(c) Aluminium

(d) Silver

 

L1Difficulty 3

QTags Mechanical

QCereator Paper Maker 10

 

 

 

Solutions

 

 

S1. Ans (c)

Sol. A Reversible Adiabatic Process is also known as Isentropic Process. It is an idealized thermodynamic process which is adiabatic and in which the work transfers of the system are frictionless; there is no transfer of heat or of matter and the process is reversible.

S2. Ans (c)

S3. Ans (a)

S4. Ans (a)

Sol. Photochemical smog is produced when pollutants from the combustion of fossil fuels react with sunlight. The energy in the sunlight converts the pollutants into other toxic chemicals. In order for photochemical smog to form, there must be other pollutants in the air, specifically nitrous oxides and other volatile organic compounds (VOCs).

 

S5. Ans (b)

Sol.  Due to density of sea water is more than that of river water, hence more volume of boat has to be sunk in the river water than that in sea water.so floor level will fall of boat in sea water.

 

S6. Ans.(c)

Sol. Pure shear strain condition depicts, shear strain  and normal strain

 

S7. Ans.(d)

Sol. As long column fails in buckling only, Euler formula also derived at the same assumption.

 

S8. (b)

Sol. Refer the table below,

Sr.no. Type of gear Normal speed ratio Efficiency
1 Spur 1:1 to 6:1 94 to 98
2 Helical 10:1 94 to 98
3 Straight bevel 5: 1 93 to 97
4 Spiral bevel 4: 1 95 to 99
5 Worm 75: 1 to 100: 1 50 to 60
6 Hypoid 10: 1 to 100: 1 80 to 95
7 Cycloid 10: 1 to 100: 1 75 to 85

 

 

S9. Ans.(a)

 

S10. Ans.(c)

Sol. As metal with high melting point cannot be casted by hot chamber die casting due to die material design temperature limit. In the above options, Aluminium has melting point is about 660  which is more than other metal (given in option).In cold chamber die casting furnace and crucible are separate parts, apart from die.

 

 

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