Company: Airports Authority of India (AAI)

AAI Previous years questions

Total 100 Qns. Around 50 technical . Only 28 of the technical is added here. Some of the questions are not complete.

1.Which of the following schemes have the best error performance with the same energy per bit?

2Same Antenna is used for Tx and Rx. Radar range related to Antenna gain as
a.Directly prop. To G
bDirec. Prop. To sq. root of G
c.Inversely prop to G

3.Thermal Noise in conductor related to B
d.Square root of B

4.A control system with feedback gains 0.1 and forward gains 10. What is the sensitivity of the system w.r.t the feedback system?

5.The value of ‘k’ for the system to be stable is. ( 6th degree Characteristic Eqn given)

6.Which of the following system is stable?
a.As2 + Bs +C
b.As2 – Bs +C
c.As4 + B s3 +Cs+D
d.As2 – Bs -C

7.Linux OS based on which architecture

8.Comparison betweeb Macro and Subroutine
a.Macro better that Sub Rtne with respect to storage time and execution time
b.Vice versa
c.Macro better that Sub Rtne with respect to execution time only
d.Vice versa

9.Which of the following is a privileged instruction?
b.INT 21
d.IN 08

10.Which of the following instruction is not converted to binary by an Assebly Language Program?
c.Privilige instruction

11.In which type of machine can multiple tasks be done

12.Which of the following has the highest distortion?

13.Which of the following distortions occur in Class B push pull amplifier?

14.Ө(s)/T(s) of a rotational system (J,B,k regular notaions)

15.Schmitt Trigger with 3V & 1V UTP and LTP respectively. A sinusoidal input with 10V peak is fed as the input.
The output swings between

16.Op-amp circuit given. Identify the circuit (Ans: Peak detector)

17.6 bit binary ladder with 101001 as input ( 0= 0V , 1 = 10V). Output voltage is ——

18.Doppler Radar of 1125 MHz. Frequency of received echo is 125 MHz. The conclusion is
a.Target also has a radar
b.Target moving away
c.Target approaching

19.Microprocessor cycles between
a.Fetch and Execution operations.
b.Fetch and Halt

20.Modulation index of an FM system with 2.5V, 500 Hz input and 5KHz deviation is

21Routh’s Criterion gives
a.Number of roots on the LHS of S plane
b.Number of roots on the RHS of S plane

22.For the system to be stable, the roots of the characteristic Equation must lie
a.Left side of the S plane
b.Right side of s plane

23.Impulse response h(t) of a system is
a.Inverse Laplace transform of Transfer Function

24.The output of a LTI system with Guassian process input is

25.Spectral Density and Auto-Correlation are
a.Laplace Transform pair
b.Fourier Transform Pair.

26.A flex Klystron is a
a.Microwave amp
b.Microwave Oscillator
c.Both amp and Oscillator
d.High cavity tube

27.S Matrix related question.

28.Block diagram givenOscillator(1MHz) à Divider (/ 10^6) à Schmitt Trigger à Flip Flop à. Output is
aPulse Train of width 1 sec
b.Pulse Train of width 2 sec
c.Pulse Train of width 0.5 sec

28. Another name of Chanakya is. Ans. Vishnugupta

29. HVDC is preferred to EHV Transmission y?

30. Given Kv=some value, Kp =0and Ka=infinity,system is of which type

31. Find Wn and delta of Transfer Function

32 Power Electrnx Problems(Tough)

33. What is DMA?

34. Network Analysis Problems

35. A switch s is closed at t=0,what is the value of L at t=0+?

36. Ratio of eddy current loss to hysteresis loss when B is changed.

37 . Machines problem.

38. Hall effect is used to determine? Ans type of the conductor.

39. Questions based on cb, cc, Ce configurations?

40. Questions based on voltage amps?

41. Max efficiency obtained from class A amplifier? Ans 50%

42To transmit a signal of 1000 Hz among these which type of filter is used? Ans all pass

43. Major questions came from antennas, waveguides, microwave oscillators, mw strips, mw devices, and etc?

44. Phase shift required for oscillations? Ans 0 or 90

45 About wave propagation in different layers?

46. Radiation pattern of antennas?

47. Questions on op and ip resistances of feed back amps?

48 Questions on jfet?

49 .Question on scr?

50 Question on slot antenna?

51. Question on range of a radar?

52. Based on filters?

53 A question on network?

54 ROM is non volatile storage device?

55RAM is not used for long storage puprose because. When power is lost we loose the memory?

56 Non programmable device is 8212?

57 7400 is Quad NAND gate?

58 NMOS cutooff voltage?

59 Yagi uda antenna radiation pattern is?

60 Helical antenna is used in satellite becoz in RC phaseshift oscillator a condition to get oscillations in hfe>= 4K+23+29/K.
If there are 8 sections in RC phase shift oscillator then each section has a phase shift of 45degrees directivity of half wave dipole is 1.64?

61 Voltage series has input impedance is high and output impedance is low?

62 READY signal is used in MP because of slow devices connected?

63TRAP is non maskable interrupt?

64 There are several 1K byte memory devices to be connected to memory chips and address lines connected to be are AD0–AD9.

65 When on write signal if a pulse is from low to high then the address/data bus lines contains.

65 RAM serves the function of