Solved Paper Junior Engineer (JE) Mechanical 2018 [Part-1] – HPSSC Hamirpur

Solved Paper Junior Engineer (JE) Mechanical 2018

Series: A

Post Code: 696

Note: Answers are given according to the official provisional answer key. Give us feedback in the comment section, if any question is answered wrong. 

1. The initial tension (in newton) in a bolt used for making a fluid tight joint like steam engine cover joints is calculated by which of the following relation in which ‘d’ is the nominal diameter of bolts in mm.

1. 1420 d
2. 1680 d
3. 2080 d
4. 2840 d

2. Welding takes place by

1. Coalescence between the parts to be joined
2. Surface joining the parts to be united by fusion of the filler rod.
3. Surface tension between two parts
4. None of these

3. The core diameter of the thread is equal to which of the following in which ‘d’ is the diameter of the bolt?

1. 58 d
2. 68 d
3. 84 d
4. 94 d

4. Square thread is usually found on

1. Spindle of bench vice
2. Railway carriage couplings
3. Feed mechanism of machine tools
4. Screw outline lathes

5. The unit of modulus of elasticity is same as those of

1. Stress, strain and pressure
2. Stress, force and modulus of rigidity
3. Strain, force and pressure
4. Stress, pressure and modulus of rigidity

6. The shear force of a cantilever beam of length ‘l’ carrying a uniformly distributed load of wper unit length is—————-at the free end

1. Zero
2. Wl/4
3. Wl/2
4. Wl

7. The hoop stress in a thin cylindrical shell is

1. Longitudinal stress
2. Compressive stress
3. Radial stress
4. Circumferential tensile stress

8. According to Euler’s column theory, the crippling load for a column of length ‘l’ hinged at both end is

1. Pie2El/l2
2. Pie2El/4l2
3. 4pieEl/l2
4. 2pie2El/l2

9. The assumption made in Euler’s column theory is that

1. The failure of the column occur due to buckling alone
2. The length of the column is very large as compared to its cross-section dimensions
3. the column material obeys Hook’s law
4. All of these

10. Euler’s column formula holds good for

1. Short columns
2. Long columns
3. Both short and long columns
4. Weak columns

11. A column is said to be short column, when

1. Its length is very small.
2. Its cross-sectional area is small
3. The ratio of its length to the least radius of gyration is less than 80
4. The ratio of its length to the least radius of gyration is more than 80.

12. The material in which the atoms are arranged chaotically is called

1. Amorphous material
2. Mesomorphous material
3. Crystalline material
4. None of these

13. The material in which the atoms are arranged regularly in some directions but not in orders is called

1. Amorphous material
2. Mesomorphous material
3. Crystalline material
4. None of these

14. The purpose of heat treatment is to

1. Relieve the stresses set up in the material after hot or cold working
2. Modify the structure of the material
3. Change the grin size
4. Any one of these

15. A perfect black body is one which

1. Is black in colour
2. Absorbs heat radiations of all wavelengths falling on it
3. Reflects all the heat radiations
4. Transmits the heat radiations

16. The unit of Stefan-Boltzmann constant is

1. Watt/mK
2. Watt/m2K2
3. Watt/m2K4
4. Watt/mK2

17. Reynold number is the ratio of

1. Energy transferred by convection to that by conduction
2. Kinematic viscosity to the thermal conductivity
3. Inertia force to viscous force
4. None of these

18. The specific gravity of water is

1. 0.001
2. 0.01
3. 0.1
4. 1

19. The specific weight of water the S.I. units is taken as

1. 81kN/m3
2. 81 * 10^3N/m3
3. 81 * 10^-6 N/mm3
4. Any one of these

20. The by-pass factor of a cooling coil decrease with:

1. Decrease in fin spacing and increase in number of rows
2. Increase in fin spacing and increase in number of rows
3. Increase in fin spacing and decrease in number of rows
4. Decrease in fin spacing and decrease in number of rows

21. During heating and dehumidification process dry bulb temperature

1. Remain constant
2. Increase
3. Decrease
4. None of these

22. The centrifugal compressors are generally used for refrigerants that require

1. Smaller displacements and low condensing pressures
2. Large displacements and high condensing pressures
3. Small displacements and high condensing pressure
4. Large displacements and low condensing pressures

23. The mass per unit volume of a liquid at a standard temperature and pressure is called

1. Specific volume
2. Mass density
3. Specific gravity
4. None of these

24. The intensity of pressure at any point in a liquid is

1. Directly proportional to the area of the vessel containing liquid
2. Directly proportional to the depth of the liquid from the surface
3. Directly proportional to the length of the vessel containing liquid
4. Inversely proportional to the depth of the liquid from the surface

25. The Bernoulli’s equation based upon the assumption that

1. There is no loss of energy of the liquid flowing
2. The velocity of flow is uniform across any cross-section of the pipe
3. No force except gravity acts on the fluid
4. All of these

26. Overall efficiency of a centrifugal pump is the ratio of

1. Energy available at the impeller to the energy supplied to the pump by the prime mover
2. Actual work done by the pump to the energy supplied to the pump by the prime mover
3. Energy supplied to the pump to the energy available at the impeller
4. Manometric head to the energy supplied by the impeller per kN of water

27. The centrifugal tension in the belts

1. Increases power transmitted
2. Decrease power transmitted
3. Have no effect of power transmitted
4. Increase power transmitted upto a certain speed and then decrease

28. The maximum fluctuation of energy is the

1. Difference between the maximum and minimum energies
2. Sum between the maximum and minimum energies
3. Variations of energies above and below the mean resisting torque line
4. Ratio of the mean resisting torque to the work done per cycle

29. Watts governor can work satisfactorily at speed from

1. 60 to 80 r.p.m.
2. 80 to 100 r.p.m
3. 100 to 200 r.p.m
4. 200 to 300 rpm

30. In the law of machine p=mw +C

1. C stand for velocity ratio
2. M stands for friction
3. C stands for friction
4. M stands for velocity ratio

31. According to Lami’s theorem

1. The three forces must be equal
2. The three forces must be at 120 degree to each other
3. The three forces must be in equilibrium
4. If the three forces acting at a point are in equilibrium, then each force is proportional to the sine of the angle between the other between the other two.

32. The centre of gravity of a quadrant of a circle lies along its central radius at a distance of

1. 0.3 R
2. 0.424 R
3. 0.5 R
4. 0.6 R

33. The co-efficient of friction is the

1. Angle between normal reaction and the resultant of normal reaction and the limiting force
2. Ration of limiting friction and normal reaction
3. The friction force acting when the body is just about to move
4. The friction force acting when the body is in friction

34. If the arm of couple is doubled, then moment of that couple would

1. Remains the same
2. Be doubled
3. Be halved
4. None of these

35. Two equal force are acting at a point with an angle of 60 degree between them the resultant is 50under root3 N, the magnitude of each force will be

1. 100 N
2. 150 N
3. 50 N
4. 50 Underroot 3 N

36. When trying to turn a key into the lock. Which of the following is applied?

1. Coplanar forces
2. Non-coplanar forces
3. Moment
4. Couple

37. A body weighing 200 N is placed on a rough horizontal plane. If the value of co-efficient of friction is 0.6  then the normal reaction will be

1. 120 N
2. 200 N
3. 150 N
4. 300 N

38. Gear lapping is an operation

1. For gear reconditioning
2. After heat treatment
3. Prior to heat treatment
4. None of these

39. Thermoplastic materials are those materials which

1. Are formed into shape under heat and pressure and result in permanently hard product
2. Do not become hard with the application of heat and pressure and no chemical change occurs
3. Are flexible and can withstand wear under suitable conditions
4. Are used as a friction lining for clutches and break

40. The stiffness of closed coil helical spring is given by S, such that S is equal to

1. Cd4/64.R4.n
2. Cd3/64.R4.n
3. Cd4/64.R3.n
4. Cd4/36.R4.n

41. A solid shaft 160 mm diameter is used to transmit the torque. The maximum shear stress induced is 50 N/mm2 , the maximum torque the shaft can transmit is

1. 128 * 10^5 pie N
2. 128 * 10^3 pie N
3. 128 * 10 ^7 pie N
4. 28 * 10^5 pie N

42. The maximum stress induced due to suddenly applied is —————— the stress induced when the same load is applied gradually.

1. Same
2. Twice
3. thrice
4. None of these

43. Moment of inertia of a circular section is

1. Πd^4/64
2. Πd^4/16
3. Πd^3/64
4. None of these

44. The bending moment of a simply supported beam of length ‘l’ carrying point load ‘W’ at the mid is equal to

1. Wl2/4
2. Wl/4
3. Wl/64
4. Wl/16

45. The factor of safety depends upon

1. Nature of loading
2. Frequency of variation of load
3. Degree of reliability required
4. All of these

46. The force is completely defined when we specify its

1. Magnitude
2. Direction
3. Point of application
4. All of these

47. Dynamic friction as compared to static is

1. Same
2. More
3. Less
4. Has no correction

48. The setting of tools in advance at a far from the machine tool or off-line in special holders is known as

1. Qualified tools
2. Semi-qualified tools
3. Pre-set tools
4. All of these

49. CAPP in CNC Machines and Automation stand for

1. Computer Aided Personnel Programming
2. Computer Aided private Programming
3. Computer Aided Part programming
4. All of these

50. A Nozzle is said to divergent nozzle

1. When the cross-section of the nozzle increases continuously from an entrance to exit
2. When the cross-section of the nozzle decrease continuously from entrance to exit
3. When the cross-section of the nozzle first decreases from entrance to throat and then increases its throat to exit
4. None of these

51. The objective of caulking in a riveted joint is to make the joint

1. Free from corrosion
2. Stronger in tension
3. Free from stresses
4. Leak-proof

52. The centre distance between two consecutive rivets in a row is called

1. Back pitch
2. Margin
3. Pitch
4. Diagonal pitch

53. The margin “m” in the rivet is given by

1. m=m 1.5 d
2. m=1.75 d
3. m=1d
4. m=2d

54. The transverse fillet weld is designed for:

1. Tensile strength
2. Compressive strength
3. Bending strength
4. Shear strength

55. A cotter is used to transmit

1. Axial tensile load only
2. Axial compressive load only
3. Combined axial and twisting loads
4. Axial tensile and compressive loads

Read next: ॥ Part – 2 ॥ Part – 3 ॥