Quiz: Mechanical Engineering 20 April 2020

Quiz: Mechanical Engineering
Exam: UPSSSC JE
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes
Q1. Hydraulic ram is a pump which works on the principle of
(a) water hammer
(b) centrifugal action
(c) reciprocating action
(d) hydraulic press

Q2. Manometer is a device used for measuring
(a) velocity at a point in a fluid
(b) pressure at a point in a fluid
(c) discharge of a fluid
(d) none of these

Q3. Consider the following statements:
The metacentric height of a floating body depends
1. directly on the shape of its water-line area
2. on the volume of liquid displaced by the body
3. on the distance between the metacentre and the centre of gravity
4. On the second moment of water-line area
Which of these statements are correct?
(a) 1 and 2
(b) 2 and 3
(c) 3 and 4
(d) 1 and 4

Q4. The predominant forces acting on an element of fluid in the boundary layer over a flat plate placed in a uniform stream include.
(a) inertia and pressure forces
(b) viscous and pressure forces
(c) viscous and body forces
(d) viscous and inertia forces

Q5. At critical point the enthalpy of vaporization is
(a) dependent on temperature only
(b) maximum
(c) minimum
(d) zero

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. Isentropic flow is_______.
(a) Reversible adiabatic flow
(b) Irreversible adiabatic flow
(c) Frictionless fluid flow
(d) None of these

Q8. Match list I with list II and select the correct answer using the codes given below the lists:
List – I                                                                                         List – II
A. Bell Coleman refrigeration                                            1. Compressor
B. Vapour compression refrigeration                              2. Generator
C. Absorption refrigeration                                                 3. Flash chamber
D. Jet refrigeration                                                                 4. Expansion cylinder
codes

A B C D
(a) 1 4 3 2
(b) 4 1 3 2
(c) 1 4 2 3
(d) 4 1 2 3

Q9. In gramophones for adjusting the speed of the turntable, the following type of governor is commonly employed
(a) Hartung governor
(b) Wilson Hartnell governor
(c) Pickering governor
(d) Inertia governor

Q10. In order to facilitate the starting of locomotive in any position, the cranks of a locomotive with two cylinders are placed at following angle to each other …………
(a) 450
(b) 900
(c) 1350
(d) 1800

SOLUTIONS

S1. Ans (a)

Sol. The working of a hydraulic ram is based on the principle of water hammer or inertia pressure developed in the supply pipe.

S2. Ans.(b)
Sol.
S3. Ans.(b)
Sol. The metacentric height depends on the volume of liquid displaced and the distance between the metacentre and the centre of gravity.
S4. Ans.(d)
Sol. Reynolds number is used to characterize flow regimes, such as laminar flow and turbulent flow. It gives measure of the ratio of inertial force to viscous force. It consequently quantities the importance of boundary layer concept
S5. Ans.(d)
Sol. At critical point enthalpy of vaporization is zero.
S6. Ans.(b)
Sol. Infinite plane’s passes through a single point. Out of infinite plane’s three planes are mutually perpendicular to each other and having zero shear stress, that planes are called principal plane.

S7. Ans.(a)

Sol.

S8. Ans.(d)
Sol.
1. Bell Coleman refrigeration: Expansion cylinder
2. Vapour compression refrigeration: compressor
3. Absorption refrigeration: Generator
4. Jet Refrigeration: Flash chamber

S9. Ans.(c)

Sol. Pickering Governor is centrifugal type governor and used in gramophone.

S10. Ans.(b)

Sol. in order to start a locomotive of two cylinders, cranks are kept at 90°.
Due to partial balancing of the reciprocating parts, there is an unbalanced primary force perpendicular to line of stroke.

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