Solved Question Paper of Recruitment Test (Computer Based Recruitment Test) conducted by UPSC for the Post of Air Safety Officer in the Office of the Directorate General of Civil Aviation held on 11.08.2019.

51.

52. Which type of fatigue is caused due to vibrations excited by jet or propeller noise?
(A) Fretting fatigue
(B) Cyclic fatigue
(C) Dynamic fatigue
(D) Acoustic fatigue

53. Which type of steel is used to manufacture aircraft arrester hooks?
(A) High carbon steel
(B) Low carbon steel
(C) Maraging steel
(D) Stainless steel

54.

55. A conductor has a constant current of five amperes. How many electrons pass a fixed point
on the conductor in one minute?

56. Two magnetically coupled coils with self inductances of 1.6 H and 0.1 H are connected in
parallel. The mutual inductance is 0.34 H. What is the effective inductance when the coils are
connected in parallel opposing?
(A) 0.0012 H
(B) 0.0187 H
(C) 0.1524 H
(D) 1.5824 H

57. A 4-pole dc machine has a lap-wound armature with 50 slots with 16 conductors per slot. The useful flux per pole is 30 mWb. What is the speed at which machine must be driven to
generate an e.m.f. of 240 V when operated as generator?
(A) 600 rev/min
(B) 500 rev/min
(C) 400 rev/min
(D) 300 rev/min

58. The wing span of a metal aeroplane is 36 m. If the aeroplane is flying at 400 kmph, what is
the e.m.f. induced between its wing tips? (Assume the vertical component of the earth’s
magnetic field is 40 Î¼T)
(A) 0.76 V
(B) 0.56 V
(C) 0.36 V
(D) 0.16 V

59. A d.c. electric motor consumes 36 MJ when connected to a 250 V supply for 1 hour. What is the amount of current drawn by the motor from mains?
(A) 0.04 A
(B) 2.4 A
(C) 40 A
(D) 2400 A

60. How much time a current of 0.1 amperes takes to transfer a charge of 30 Coulombs?
(A) 300 seconds
(B) 30 seconds
(C) 3 seconds
(D) 0.3 seconds