Electronics and Communication Engineering - Exam Questions Papers

26. 

In the given figure
.
The damped frequency is __________ .

A. 0 rad/sec
B. 2 rad/sec
C. 3/2 rad/sec
D. None of these

Answer: Option C

Explanation:

Damped frequency

ωd = 3/2.


27. 

For a medium σ = 2.1 x 10-4 mho/m and ε = 80 e0 at a frequency of 5 GHz its loss tangent is

A. 1 x 10-5
B. 9.45 x 10-6
C. 1.31 x 10-4
D.

Answer: Option B

Explanation:

= 9.45 X 10-6.


28. 

For the output F to be 1 in the logic circuit shown, the input combination should be

A. A = 1, B = 1, C = 0
B. A = 1, B = 0, C = 0
C. A = 0, B = 1, C = 0
D. A = 0, B = 0, C = 1

Answer: Option D

Explanation:

B = A

F = A⊙B⊙C = A⊙A⊙C so,

F = 1 when C = 1.


29. 

The ROC of Z-transform of the discrete time sequence x(n) is

A.
B.
C.
D. 2 > |Z| > 3

Answer: Option A

Explanation:

.


30. 

Assuming the OP-AMP to be ideal, the voltage gain of the amplifier shown in figure is

A.
B.
C.
D.

Answer: Option A

Explanation:

By rearranging