PSC Junior Instructor mechanic Motor Vehicle Model Questions and Answers

26. Which type of brake chamber is provided with fail safe parking brake?
(A) Spring brake chamber
(B) Single diaphragm brake chamber
(C) Double diaphragm brake chamber
(D) Triple diaphragm brake chamber
Answer: A

27. The propellant unit of air bag consists of
(A) Potassium chloride and silver nitrate
(B) Potassium chloride and sodium azide
(C) Potassium nitrate and sodium azide
(D) Potassium nitrate and sodium chloride
Answer: C

28. Which of the following is controls fuel surge in fuel tank on vehicle movement?
(A) Ribs
(B) Baffles
(C) Brackets
(D) Belts
Answer: B

29. Excess fuel pressure in a CRDI engine system is protected with a
(A) ECU
(B) Rail pressure sensor
(C) Pressure limiter valve
(D) Flow limiter
Answer: C

30. The function of an air cleaner
(A) Act as silencer
(B) Act as flame arrester
(C) Filtering intake air
(D) All of these
Answer: D

31. What are the basic factors affect the gear selection?
(A) Vehicle load and engine speed
(B) Vehicle speed and engine load
(C) Vehicle load and road condition
(D) Engine speed and road condition
Answer: B

32. The cavitations formed inside the torque converter centre is the result of
(A) Low oil pressure
(B) Less engine RPM
(C) Less torque conversion
(D) None of these
Answer: A

33. The plunging type constant velocity joint is employed at the …………….. end of the drive shaft.
(A) Wheel end
(B) Differential end
(C) Both (A) and (B)
(D) Main shaft end
Answer: B

34. Which of the following is not a reason for humming noise from the rear axle?
(A) Worn out differential bearings
(B) Backlash between crown and pinion
(C) Worn out gears
(D) Worn out axle shaft splines
Answer: D

35. The material used to improve the resistance to wear of rubber threads in a tire is
(A) Nylon
(B) Rayon
(C) Carbon black
(D) Terylene
Answer: C

36. Which part of a master cylinder serves to retain the residual pressure in the brake lines even when the brakes are released?
(A) Check valve
(B) Piston
(C) Piston return spring
(D) Primary cup
Answer: A

37. Lamda sensors are located at
(A) Exhaust manifold
(B) Inlet manifold
(C) Throttle body
(D) Timing cover
Answer: A

38. Sedimentation type fuel filters are generally used as
(A) Baby filter
(B) Secondary filter
(C) Primary filter
(D) All of these
Answer: C

39. Which one of the following is a cylinder head gasket material?
(A) Felcoprene
(B) Felcoid
(C) Cord
(D) Shimbestose
Answer: D

40. The ability of engine bearings to accommodates small variation in shaft is its
(A) Embadability
(B) Conformability
(C) Adaptability
(D) Fatigue strength
Answer: B

41. The device fitted on diesel engine to develop vacuum to assist the pneumatic governor of FIP
(A) Compressor
(B) Inter cooler
(C) Exhauster
(D) Super charger
Answer: C

42. Number of pole fingers in an alternator rotor
(A) 8
(B) 12
(C) 14
(D) 16
Answer: B

43. Which of the following is a solid lubricant?
(A) Graphite
(B) lead
(C) Tin
(D) Aluminium
Answer: A

44. The clearance between the oil pump gear teethes are measured with
(A) Dial gauge
(B) Vernier caliper
(C) Inside micro meter
(D) Feeler guage
Answer: D

45. Which one of the following is not affected the fuel economy of an engine?
(A) Clogged air filter
(B) Clogged fuel filter
(C) Leaky engine valves
(D) Worn out piston rings
Answer: B

46. Find the probable cause of wheel tramp
(A) High speed
(B) Under inflation
(C) Incorrect toe-in
(D) Dynamic unbalance
Answer: D

47. A vehicle with torsion bar suspension required …………….. to take the driving and braking thrust.
(A) Stabilizer bar
(B) Pan hard rod
(C) Radius rod
(D) Torque tube
Answer: C

48. Which of the under mentioned fault can be change the steering axis inclination?
(A) Bent wheel spindle
(B) Worn out knuckle bearings
(C) Bent track rod
(D) Tight wheel bearing
Answer: A

49. The effect of side wind over the frame side member is its
(A) Lateral bending
(B) Horizontal bending
(C) Vertical bending
(D) All of these
Answer: A

50. Belleville springs are generally known as
(A) Torsion springs
(B) Coil springs
(C) Helical springs
(D) Diaphragm springs
Answer: D