Electronics and Communication Engineering - Exam Questions Papers

41. 

For a = - 1, find the value of V2

A.
B. 0
C. V1
D. none of the above

Answer: Option B

Explanation:

V1 = i1R1 + i2R2

i1 + ai1 = i2

V2 = i2R2

Putting a = - 1

= 0 V.


42. 

A unity-feedback control system has the open loop transfer function . If the input system is a unit ramp, the steady state error will be

A. 0
B. 0.5
C. 2
D. infinity

Answer: Option C

Explanation:

.


43. 

For a given voltage, four heating coils will produce maximum heat when connected

A. all in parallel
B. all in series
C. with two parallel pairs in series
D. one pair in parallel with the other two in series

Answer: Option A

Explanation:

.


44. 

Denominator polynomial of a transfer function of certain network is:
s3 + s2 + 2s + 24
Then the network is:

A. stable
B. oscillatory
C. unstable
D. depends on numerator polynomial

Answer: Option C

Explanation:

Routh array

There is negative number present in first column. Thus network is unstable.


45. 

A TV picture is to be transmitted over a channel of 6 MHz bandwidth at a 35 dB S/N ratio. The capacity of the channel is

A. 50 Mbps
B. 100 Mbps
C. 36 Mbps
D. 72 Mbps

Answer: Option D

Explanation:

W = B = Bandwidth

C = 6 x 106 x 12 = 72 Mbps.