Electronics and Communication Engineering - Exam Questions Papers

Exercise :: Exam Questions Papers - Exam Paper 21
46.
A magnetic field in air is measured to be What current distribution leads to this field? [Hint: The algebra is trivial in cylindrical coordinates.]

Answer: Option C

Explanation:

47.
For a series R-L-C circuit, the characteristic equation is given as If is denoted by a and by β, then under the condition of β^{2} > a ^{2} , the system will be

A.
critically damped B.
underdamped C.
undamped D.
overdamped

Answer: Option B

Explanation:

48.
In the epitaxial diffused method of fabricating integrating circuits the process involved are __________

Epitaxial growth Diffusion Silicon diode growth Vacuum evaporation of aluminium Photoetching The correct order is

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

Answer: Option B

Explanation:

49.
The switch in the circuit shown was on position a for a long time, and is moved to position b at time t = 0. The current i (t ) for t > 0 is given by

A.
0.2e ^{-125t} u (t ) mA B.
20e ^{-1250t} u (t ) mA C.
0.2e ^{-1250t} u (t ) mA D.
20e ^{-1000t} u (t ) mA

Answer: Option B

Explanation:

50.
For a standard 2nd order system the maximum overshoot is 10% to an unit step input. If the magnitude of the input is doubled, then maximum overshoot and percentage of maximum overshoot is:

A.
maximum overshoot doubles and percentage of maximum overshoot is less than double B.
maximum overshoot doubles and percentage of maximum overshoot do not change C.
maximum overshoot remain same and percentage of maximum overshoot is double D.
maximum overshoot more than double and percentage of maximum overshoot is less than double

Answer: Option B

Explanation: