Electronics and Communication Engineering - Exam Questions Papers

41. 

The system shown in figure remains stable when :

A. k £ - 1
B. -1 < k < 1
C. l < k < 3
D. k > 3

Answer: Option D

Explanation:

Pi = 1 x k x s-1 x 1 ⇒

, L2 = k x s-1

System will be stable when k - 3 > 0 or k > 3.


42. 

The mechanical system shown below has its pole(s) at:

A. - K/D
B. - D/K
C. - DK
D. 0, - K/D

Answer: Option A

Explanation:

Kx(s) - Ky(s) = Dsy(s)

Kx(s) = Dsy(s) + Ky(s)


43. 

The step error coefficient of a system with unity feedback is :

A. 1/6
B.
C. 0
D. 1

Answer: Option A

Explanation:

kp = s → 0 G(s)H(s).


44. 

The following k-map implements

A. BCD to Decimal Decoder
B. Decimal to BCD Encoder
C. 1 of 10 Decoder
D. (a) and (c)

Answer: Option D

Explanation:

As the K-map reveals W, X, Y, Z are the input lines to the device and D0 to D9 are the output lines which get activated depending upon the input combinations.

As seen from k-map for W, X, Y, Z from 0000 to 1001 we have D0 to D9 outputs activated respectively.

This operation is performed by BCD to Decimal decoder.

Also it is called as 1 off 10 decoder, as only 1 of 10 output line is high.


45. 

The Z-transform of a signal is given by its final value is __________ .

A. infinite
B. 1/4
C. zero
D. 1

Answer: Option D

Explanation:

Final value

Final value

Final value

.