NTA UGC NET/JRF Exam, December-2019 (Electronic Science)

61. Which of the following set of instructions will lead to same result in AX register?

(a) MOV AX, 0305 H OR AX, 3030 H
(b) MOV AX, 0305 H ADD AX, 3030 H
(c) MOV AX, 0305 H XOR AX, 3030 Н
(d) MOV AX, 0305 H AND AX, 3F3 FH
Choose the correct answer:

A. (a) and (d)
B. (d) and (c)
C. (a) and (b)
D. (b) and (d)

Correct Answer: C. (a) and (b)

62. Which of the following statements are correct for 8051 micro controller?

(a) RAM location 20 H to 2 FH are set aside for bit-addressable read/write memory
(b) Bits P 3.4 and P 3.5 are used to provide the WR and RD signals of external memories
(c) Direct addressing mode is allowed for pushing onto the stack
(d) T× D and R × D pins are TTL compatible and therefore don't require line driver to make these RS 232 compatible
Choose the correct answer:

A. (a) and (d)
B. (b) and (c)
C. (a) and (c)
D. (b) and (d)

Correct Answer: C. (a) and (c)

63. A linearly polarized plane wave travelling in x-direction with 'E' in the Y-direction can be represented as

The following statements are given for the above equation
(a) It is scalar phasor equation
(b) σEᵧ represents displacement current density
(c) jw ∈ Eᵧ represents conduction current density
(d) If σ ≠ 0 and the displacement current is much greater than conduction current, the medium behaves like imperfect dielectric
Choose the correct option:

A. both (a) and (b) are correct
B. both (a) and (d) are correct
C. both (b) and (c) are correct
D. both (b) and (d) are correct

Correct Answer: B. both (a) and (d) are correct

64. Read the following statements:

A. (a) and (d) are correct
B. (a) is correct, but (b) is wrong
C. (c) and (d) are correct
D. (a) and (b) are correct

Correct Answer: D. (a) and (b) are correct

65. Consider the following statements:

(a) LASER diode generates monochromatic coherent light which reduces chromatic dispersion
(b) LASER source is useful for high power long distance optical communication
(c) LASERS have longer life time than LEDS
(d) LASER diodes are less temperature sensitive than LEDs
Which of the above statements are correct?

A. (a) and (b)
B. (a) and (c)
C. (b) and (d)
D. (b) and (c)

Correct Answer: A. (a) and (b)

66. Read the following expression regarding mutual informations I(X, Y):

(a) I(X;Y) = H(X) – H(Y/X)
(b), I(X;Y) = H(X) – H(X/Y)
(c) I(X;Y) = H(X) + H(Y) – H(X,Y)
(d) I(X;Y) = H(X) + H(Y) + H(X,Y)
Which of the above expressions are correct?

A. (a) and (c)
B. (b) and (c)
C. (a) and (d)
D. (b) and (d)

Correct Answer: B. (b) and (c)

67. Consider the following statements regarding the steady state error of type '0' system.

A. (à) and (b)
B. (a) and (c)
C. (b) and (c)
D. (a) and (d)

Correct Answer: D. (a) and (d)

68. Following statements are given for DC motors:

(a) DC motors require less maintenance than AC motors
(b) DC motors cannot provide high starting torque
(c) DC motors are not suitable for very high speed applications
(d) The methods of speed control of DC motors are simpler and less expensive than those of AC motors
Which of the following statements are correct?

A. (a) and (c)
B. (a) and (b)
C. (b) and (c)
D. (c) and (d)

Correct Answer: D. (c) and (d)

69. A list of different resistor configurations are given below:

(a) Shunt resistor
(b) Series multiplier resistor
(c) Ayrton shunt
(d) Swamping resistor
Which of the above are used in DC Ammeter?

A. (a) and (b)
B. (b) and (d)
C. (b) and (c)
D. (a) and (c)

Correct Answer: D. (a) and (c)

70. List of different transducers are given below

(a) Hot-wire meter DT
(b) Ionization chamber
(c) Magnetostriction gage
(d) Photoconductive cell
Which of the above are passive transducers D producing variation in resistance?