Exam: SSC JE
Topic: Miscellaneous
Each question carries 1 mark.
Negative marking: 1/4 mark
Time: 10 Minute
Q1. PMM1 violates which law of thermodynamics
(a) First law
(b) Second law
(c) Third law
(d) none of these
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q2. In S.I. engine knocking occurs due to
(a) High coolant temperature
(b) Low coolant temperature
(c) High speed of the engine
(d) High self-ignition temperature of fuel
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q3. Stagnation head in Pitot tube is
(a) Static head + dynamic head
(b) Equal to Static head
(c) Equal to Dynamic head
(d) Equal to loss of head
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q4. Laminar flow is also known as
(a) Steady flow
(b) Viscous flow
(c) Turbulent flow
(d) Uniform flow
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q5. Fourneyron Turbine is a type of
(a) Axial turbine
(b) Inward flow radial turbine
(c) Outward flow radial turbine
(d) Impulse turbine
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q6. In on-off control refrigeration system, which one of the following expansion devices is used?
(a) Thermostat
(b) Capillary tube
(c) Automatic expansion valve
(d) Float Valve
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q7. When a rectangular beam is loaded longitudinally, shear develops on
(a) Top fiber
(b) Bottom fiber
(c) Middle fiber
(d) Every horizontal plane
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q8. The Corriollis’ component of acceleration is always
(a) Perpendicular to link
(b) Parallel to link
(c) Radially outward along link
(d) Coincident with the axis of link
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q9. Neutral flame is used to weld metal like
(a) Aluminium
(b) Structural steel
(c) Brass
(d) Cast iron
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q10. If feed per revolution is 2 mm and lathe spindle is rotating with 600 rpm then find out the time taken to machine 400 mm length workpiece
(a) 0.33 sec
(b) 20 sec
(c) 2 min
(d) 1.33 sec
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Solutions
S1. Ans (a)
Sol. PMM1 is a machine which can produce an amount of useful energy without consuming any external work. Which is impossible according to First law of Thermodynamics.
S2. Ans (a)
Sol.
Following are some reasons of knocking in S.I. engine-
1-High coolant temperature
2-High compression ratio
3-Low speed of engine
4-Low self-ignition temperature of the fuel
S3. Ans (a)
S4. Ans (b)
Sol. Laminar flow is a highly viscous flow.
S5. Ans (c)
S6. Ans.(a)
Sol. Thermostat works on the principle of constant degree of superheat at evaporator outlet & used to on-off AC according to this.
S7. Ans.(d)
Sol. Shear stress and strain always acts parallel to force applied. (longitudinally given)
S8. Ans.(a)
S9. Ans.(b)
S10. Ans.(b)
Sol.
N=600 rpm
L=400 mm
Feed per rev= 2 mm
Time taken to machine the component==
=0.33 minute or 20 sec
