# Electronics and Communication Engineering - Exam Questions Papers

1.

Assertion (A): The expression E = - ΔV, where E is the electric field and V is the potential is not valid for time varying fields.

Reason (R): The curl of a gradient is identically zero.

Both A and R are individually true and R is the correct explanation of A
Both A and R are individually true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Explanation:
No answer description is available. Let's discuss.

2.
At 20 GHz , the gain of a parabolic dish antenna of 1 meter diameter and 70% efficiency is
15 dB
25 dB
35 dB
45 dB
Explanation:
No answer description is available. Let's discuss.

3.
Hysteresis loss in a transformer working at 220 V and at a frequency of 50 Hz is 100 W. When the transformer is operated at 220 V and at a frequency of 100 Hz, what is the hysteresis loss?
50 W
100 W
200 W
400 W
Explanation:
No answer description is available. Let's discuss.

4.
Given the transfer function

Polar plot will be of shape.