Electronics and Communication Engineering - Networks Analysis and Synthesis

41. 

The time constant of the circuit in figure shown.

A. RC
B.
C.
D.

Answer: Option B

Explanation:

Time constant Req.C

when V is shorted and R is seen from C then Req = R || R = R/2

.


42. 

In the circuit shown in given figure, the values of i(0+) and I(∞), will be respectively

A. zero and 1.5 A
B. 1.5 A and 3 A
C. 3 A and zero
D. 3 A and 1.5 A

Answer: Option C

Explanation:

I(t) = 6 e-t - 3 e-0.5t

at t = 0, I(0) = 3A

at t = ∞, I(∞) = 0.


43. 

A two branch parallel circuit has a 20 Ω resistance and 1 H inductance in one branch and a 100 μF capacitor in the second branch. It is fed from 100 V ac supply, at resonance, the input impedance of the circuit is

A. 500 Ω
B. 50 Ω
C. 20 Ω
D. 5 Ω

Answer: Option A

Explanation:

At parallel resonance circuit impedance = .


44. 

The impedance matrices of two, two-port network are given by and . If these two networks are connected in series, the impedance matrix of the resulting two-port network will be

A.
B.
C.
D. indeterminate

Answer: Option B

Explanation:

Impedance matrices will be added.


45. 

As compared to the number of network elements in Brune synthesis, the number of network elements Bott-and Duffin in realization is

A. more
B. less
C. equal
D. any of the above

Answer: Option A

Explanation:

To avoid mutually coupled inductors, more elements are needed.