Electronics and Communication Engineering - Exam Questions Papers

16. 

With which decoder it is possible to obtain many code conversions?

A. 2 line to 4 line
B. 3 line to 8 line
C. not possible with any decoder
D. 4 line to 16 line decoder

Answer: Option D

Explanation:

No answer description available for this question. Let us discuss.

17. 

Consider the following statements:
The klystron and travelling wave tube differ from each other,

  1. In TWT the microwave circuit is non- resonant.
  2. In klystron the microwave circuit is resonant.
  3. TWT uses attenuator.
  4. The wave is TWT is a non-propagating wave.
Which of the above statements are correct?

A. 1 and 2 only
B. 3 and 4 only
C. 1, 2 and 3
D. 2, 3 and 4

Answer: Option C

Explanation:

No answer description available for this question. Let us discuss.

18. 

Consider a system whose input x and output y are related by the equation
y(t) = x(t - t)h(2t)dt
where h(t) is shown in the graph
which of the following four properties are possessed by the system?
BIBO: Bounded input gives a bounded output
Causal: The system is causal
LP: The system is low pass
LTI: The system is linear and time invariant

A. Causal, LP
B. BIBO, LTI
C. BIBO, Causal, LTI
D. LP, LTI

Answer: Option B

Explanation:

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19. 

The following components are used to measure power output of a 2 kW TWT amplifier:

  1. TWTA
  2. Low pass/high pass filter
  3. 20 dB attenuator
  4. 40 dB directional complex with matched load
  5. Power load
What is the correct sequence of connection of these components?

A. 2 - 4 - 1 - 3 - 5
B. 1 - 3 - 4 - 2 - 5
C. 1 - 2 - 4 - 3 - 5
D. 2 - 4 - 1 - 5 - 3

Answer: Option B

Explanation:

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20. 

Consider the following statements regarding sources or error in a Q-meter:

  1. If a coil with resistance R is connected in direct measurement mode and if the residual resistance of Q-meter is 0.1 R, then the measure Q of the coil would be 1.1 times the actual Q.
  2. If the inductance to be measured is less than 0.1 mH, the error due to presence of residual inductance cannot be neglected.
  3. The presence of distributed capacitance in a coil modifies the effective Q of the coil.
Which of the above statements are correct?

A. 1, 2 and 3
B. 1 and 2 only
C. 2 and 3 only
D. 1 and 3 only

Answer: Option C

Explanation:

No answer description available for this question. Let us discuss.