Typical Questions on Diploma Electronics Engineering

1. A 400 W carrier is modulated to a depth of 75 percent. The total power in modulated wave will be
(a) 38.5 W
(b) 400 W
(c) 512.5 W
(d) 615.5 W

2. In a PCM system, if we increase the quantization levels from 2 to 8, how do the relative bandwidth requirements vary?
(a) Get doubled
(b) Get tripled
(c) Remain same
(d) Become eight times

3. Which of the following parameters is negligible in transmission lines?
(a) R
(b) L
(c) C
(d) G

4. The beam of a radar should be
(a) Very narrow
(b) Very wide
(c) Neither too narrow nor too wide
(d) Either (b) or (c)

5. A duplexer is used to
(a) Couple two antennas to a transmitter
(b) Isolate the antenna from the local oscillator
(c) Prevent interference between two antennas connected to receiver
(d) Use an antenna for reception or transmission without interference

6. A waveguide section in a microwave circuit acts as
(a) LP filter
(b) Bandpass filter
(c) HP filter
(d) Bandstop filter

7. Impedance inversion may be obtained with
(a) A short circuited stub
(b) A quarter wave line
(c) An open circuited stub
(d) A half wave line

8. Which of the following is not a negative resistance device?
(a) Gunn diode
(b) Tunnel diode
(c) Impatt diode
(d) Varactor diode

9. In a klystron amplifier the force on all electrons
(a) Causes acceleration of all electrons
(b) Causes retardation of all electrons
(c) Causes acceleration of some electrons and retardation of others
(d) None of the above

10. If word length is 16 bits the decimal equivalent of largest number which can be stored is
(a) 32767
(b) 32766
(c) 16383
(d) 16384

11. The decimal equivalent of binary 1101.11 is
(a) 9.75
(b) 13.75
(c) 11.50
(d) 11.75

12. The maximum number of characters for variable names in C is
(a) 4
(b) 8
(c) 12
(d) 16

13. For accurate clock period in 8085 it is preferable to use
(a) Crystal
(b) Crystal of LC resonant circuit
(c) Crystal of RC circuit
(d) LC or RC circuit

14. In 8085 stack pointer is
(a) 4 bit register
(b) 8 bit register
(c) 16 bit register
(d) 32 bit register

15. 8255 is a
(a) Programmable peripheral interface
(b) I/O device
(c) Memory chip
(d) None of these

16. The number of pins in microprocessor 8086 is
(a) 30
(b) 40
(c) 50
(d) 60

17. For AM receivers the standard IF frequency is
(a) 106 KHz
(b) 455 KHz
(c) 1.07 MHz
(d) 10.7 MHz

18. If a line is terminated in characteristic impedance Zo; the input impedance measured at the input will be
(a) Zo
(b) Zo/2
(c) Zero
(d) infinite

19. Which of the following is analog in nature?
(a) PCM
(b) PWM
(c) delta modulation
(d) differential PCM

20. Which of the following is taken as reference antenna for directive gain?
(a) ½ wave dipole
(b) elementary doublet
(c) isotropic antenna
(d) infinitesimal dipole

21. To separate channels in FDM receivers we have to use
(a) integration
(b) AND gate
(c) band pass filter
(d) differentiation

22. The characteristic impedance of a cable is about
(a) 2
(b) 5
(c) 50
(d) 300

23. Most electromagnetic transmission in rectangular waveguide uses
(a) TE10 mode
(b) TE01 mode
(c) TE20 mode
(d) TE11 mode

24. What is the numerical aperture in an optical fiber when critical angle is 30°?
(a) 0.5
(b) 0.707
(c) 0.866
(d) 0.2

25. In a Klystron amplifier the input cavity is called
(a) Buncher
(b) Catcher
(c) pierce gun
(d) collector

More Question Set on Electronics Engineering Diploma MCQs from Various Exam

26. Which of the following computer memories is fastest?
(a) Cache
(b) Primary
(c) mass storage
(d) backup memories

27. The number of interrupt lines in 8085 microprocessor is
(a) 3
(b) 4
(c) 5
(d) 7

28. The data structure needed to convert infix notation to prefix notation is
(a) Queue
(b) Stack
(c) Tree
(d) graph

29. Quantizing noise occurs in
(a) TDM
(b) FDM
(c) PWM
(d) PCM

30. Which signaling scheme is most affected by noise?
(a) ASK
(b) FSK
(c) PSK
(d) QAM

31. A matched load is one in which
(a) reflection is zero
(b) reflection is unity
(c) partial reflection
(d) none of these

32. Which principle of operation of cavity wave meters is used in microwave networks?
(a) phase shift
(b) resonance
(c) polarisation shift
(d) gyration

33. A sinusoidal voltage of 2 kV peak value is amplitude modulated to give 20% modulation. The peak value of each side band term is
(a) 800V
(b) 400V
(c) 200V
(d) 100V

34. In the FM wave described by equation v = 15 sin (4 × 108 t + 3 sin 1100 t), the maximum frequency deviation is
(a) 175 Hz
(b) 525 Hz
(c) 58.33 Hz
(d) 3 Hz

35. Narrowband FM signal can be considered to be equal to
(a) PM
(b) AM
(c) SSB
(d) DSB

36. The bandwidth of DSB suppressed carrier modulation system when the modulating frequency varies between 500 Hz and 5 kHz is
(a) 555 kHz
(b) 505 kHz
(c) 500 kHz
(d) 9 kHz

37. The velocity of sound waves in air
(a) is constant at all temperatures
(b) varies directly as temperature
(c) varies inversely as absolute temperature
(d) varies directly as square root of absolute temperature

38. Troposphere is the portion of atmosphere
(a) nearest to ground
(b) between 50 to 90 km above ground
(c) between 110 to 220 km above ground
(d) between 250 to 350 km above ground

39. Light may be propagated along a fiber-optic cable in which of the following modes?
(a) multimode step index
(b) single-mode step index
(c) multimode graded index
(d) all of these

40. A television (TV) transmission is an example of which type of transmission?
(a) Simplex
(b) Half duplex
(c) Full duplex
(d) None of these

41. INTELSAT stands for
(a) International Telecommunications Satellite
(b) India Telecommunications Satellite
(c) Inter Telecommunications Satellite
(d) None of these

42. Kepler’s first law states
(a) The path followed by a satellite around the primary will be an ellipse.
(b) The path followed by a satellite around the primary will be a circle.
(c) The path followed by a satellite around the primary will be a sphere
(d) None of the above

43. An instruction used to set the carry flag in a computer can be classified as
(a) Data transfer
(b) Arithmetic
(c) Logical
(d) Program control

44. In the 8085 microprocessor the RST6 instruction transfers the program execution to the following locations
(a) 30H
(b) 24H
(c) 48H
(d) 60H

45. The highest priority of interrupt in 8085 microprocessor system is
(a) RST 7.5
(b) RST 6.5
(c) INTR
(d) TRAP

46. For a reflection coefficient of 0.5, the value of SWR is
(a) –1
(b) 1
(c) 2
(d) 3

47. For a distortionless line, the parameters are related as
(a) R/G=L/C
(b) R/L=I
(c) R/G=C/L
(d) RG=LC

48. Polarisation of a wave is
(a) Direction of electric field
(b) Direction of magnetic field at some point in space
(c) Either (a) or (b)
(d) None of these

49. The maximum theoretical efficiency of a class A amplifier is
(a) 12.5%
(b) 25%
(c) 50%
(d) 75%

50. A Hartley oscillator uses
(a) A tapped inductor
(b) A tapped capacitor
(c) Both (a) and (b)
(d) Neither (a) nor (b)