Electronics and Communication Engineering - Exam Questions Papers

11. 

Find the voltage across 64 Ω resistor

A. V
B. V
C. V
D. V

Answer: Option C

Explanation:

Voltage across 64 Ω is = 1x=V.


12. 

If f(Z) = c0 + c1z-1, then is given by

A. 2pc1
B. 2p (1 + c0)
C. 2pjc1
D. 2pj(1 + c0)

Answer: Option D

Explanation:


13. 

The capacitors C1, C3, C4 and C5 have a capacitance of 4 μF each and the capacitor C2 has a capacitance of 10 μF. The effective capacitance (in μF) between the points X and Y will be

A. 4 μF
B. 6 μF
C. 3 μF
D. 8 μF

Answer: Option A

Explanation:

Converting into T network


14. 

(9)11 x (9)13 x(9)15 = (?)16

A. 933
B. 2D9
C. 339
D. 9AB

Answer: Option B

Explanation:

(9 x 9 x 9)15 = (729)15 = (2D9)16 .


15. 

The equivalent T circuit of this coupled network is shown in figure. Find the values of ZA, ZB and ZC.

A. -j, 6j, 2j
B. -j, 2j, 6j
C. j, 2j, - 6j
D. j, 2j, 6j

Answer: Option B

Explanation:

Use mesh analysis for the coupled network

Apply KVL at loop 1

V1 = 5jI1 + 6jI2

Apply KVL to loop 2

V2 = 8jI2 + 6jI1

Consider given T network

Apply KVL to mesh 1

V1 = (ZA + ZC)I1 + ZCI2

Apply KVL to mesh 2

V2 = (ZB + ZC)I2 + ZCI1

Compare equation (i) and (iii)

ZA + ZC = 5j and ZA = 6j

ZA = - j

Compare equation (ii) and (iv)

ZB + ZC = 8j

ZB + j = 8j

ZB = 2j

ZA = - j ZB = 2j ZC = 6j.