Question 1

and i(t) is a unit step, then V(t) in the steady state is given by

Accepted Answer

= 4/9.

Question 2

Which of the following pairs are correctly matched? Brune's realisation : realisation with ideal transformer. Cauer realisation : ladder realisation. Bott Duffin realisation : with non ideal transformer. Select the answer using the following codes:

Accepted Answer

Bott Duffins realisation does not use transformer.

Question 3

In a minimum function

Accepted Answer

If degrees of numerator and denominator were unequal, a pole or zero can be removed. Such a function cannot be a minimum function. Therefore degrees of numerator and denominator must be equal.

Question 4

An RLC series circuit is underdamped. To make it overdamped, the value of R

Accepted Answer

For overdamping R is more.

Question 5

A sinusoidal voltage has peak to peak value of 100 V. The rms value is

Accepted Answer

Peak value = 50 V, rms value = = 35.35 V.

Question 6

A series RC circuit has R = 5 Ω and C = 10 μF. The current in the circuit is 5 sin 20000t. The applied voltage is

Accepted Answer

Z = R2 + XC2 = 50 V = 550 sin(20000 t - 45°) V = 252 sin(20000 t - 45°)

Question 7

A 3 phase balanced supply feeds 3 phase unbalanced load. Power supplied to the load can be measured by using 2 wattmeter one wattmeter 3 wattmeter Which of the above statements is correct?

Accepted Answer

A minimum of 2 wattmeters is required to measure 3 phase power. Of course power can be measured by putting one wattmeter in each phase.

Question 8

The driving-point impedance Z(s) of a network has a pole-zero locations as shown in the figure. If Z(0) = 3, then Z (s) is

Accepted Answer

From figure, The impedance function and Z(0) = while in question Z(0) = 3 ⟹ = 3 ⟹ k = 2.

Question 9

The degree of the nodes 1, 2, 3, 4 is

Accepted Answer

Degree of node is the no.of branch incident to it.

Question 10

In the circuit of figure the voltage across capacitor when switch is closed at t = ∞ is

Accepted Answer

Voltage across capacitor = voltage across 3Ω resistance =

Question 11

C = (2) (energy)/V2

Accepted Answer

Question 12

A capacitor stores 0.15C at 5 V. Its capacitance is

Accepted Answer

Q = CV or 0.15 = C(5) or C = 0.03 F.

Question 13

The impedance of an RC series circuit is 12 Ω at f= 50 Hz. At f= 200 Hz, the impedance will be

Accepted Answer

Z = R2 + XC2. When f is made four times, XC becomes one-fourth but R remains the same.

Question 14

In the series circuit shown in figure, for series resonance, the value of the coupling coefficient, K will be

Accepted Answer

Mutual inductance wm = ωk L1L2 ⟹ m = k. 2. 8j2 = 4k. j Z = 20 - j10 + j2 + j6 + 2.4kj - 2j + 8kj = 0 at resonance ⟹ -2 = -8k k = 1/4 ⟹ 0.25 .

Question 15

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

Accepted Answer

To avoid mutually coupled inductors, more elements are needed.

Question 16

Two networks are cascaded through an ideal buffer. If td1 and td2 are delay times of network, the overall delay time is

Accepted Answer

In cascaded networks delay times are added.

Question 17

A capacitor is needed for an ac circuit of 230 V, 50 Hz the peak voltage rating of the capacitor should be

Accepted Answer

Peak voltage rating = 2 (rms voltage rating).

Question 18

For node 1 in figure, KCL equation is

Accepted Answer

i(t) is the incoming current. The currents leaving node 1 are

Question 19

Which of the following is correct for a driving point functions?

Accepted Answer

It is a necessary condition for response to be stable.

Networks Analysis and Synthesis Questions