Network Theory Laboratory Viva Questions 5

1. Which of the following truly reflects the power condition in a purely inductive circuit in which an RMS current of „I‟ A is flowing due to a sinusoidal RMS voltage „V‟ volt?

(A) P = VI sin 90° and Q = VI sin 90°

(B) P = VI sin 90° and Q = VI cos 90°

(C) P = VI cos 90° and Q = VI sin 90°

(D) P = VI cos 90° and Q = VI cos 90°

Answer : [C] P = VI cos 90° and Q = VI sin 90°

2. Which of the following holds when a sinusoidal voltage is applied to a pure inductance?

(A) In one half-cycle energy is absorbed

(B) In the next half-cycle energy is released

(C) Continuous exchange of energy

(D) All of these

Answer : [D] All of these

3. Which of the following is an advantage of using Laplace transform techniques?

(A) Permits use of simple algebra

(B) Converts functions in the time-domain into s-domain

(C) Initial conditions are automatically taken care of

(D) Both (A) & (B)

(E) All of the above

Answer : [E] All of the above

4. Which of the following represents correctly the Laplace transform of a step function defined from t=0 onwards and having the magnitude 4?

(A) 4

(B) 4 e −3s

(C) 4 e 3s

(D) 4 /s

(E) 4 e −3s /(s − 3)

(F) 4 e −3s /s

Answer : [D] 4 /s

5. Which of the following is a characteristic of a unit impulse function?

(A) Infinite amplitude

(B) Unit area

(C) Zero time duration

(D) All of these

(E) Both (B) & (C)

Answer : [D] All of these

6. In order to analyze a two-port network which of the following is the essential combination?

(A) Four independent variables and four parameters

(B) Four independent variables and two parameters

(C) Two independent variables and four parameters

(D) Two independent variables and two parameters

(E) All of the above

(F) None of the above

Answer : [C] Two independent variables and four parameters

7. A particular 2-port network has following transmission parameters, A = 5, B = 6, C =5, D= 7.

Then the two-port system is

(A) Reciprocal & Symmetrical

(B) Non reciprocal & Asymmetrical

(D) Non reciprocal & Symmetrical

(E) Reciprocal & Asymmetrical

(C) None

(F) All of the above

Answer : [B] Non reciprocal & Asymmetrical

8. The parallel combination of a capacitor C farads and an inductor L Henry is connected in

series with a resistor of R Ω. Which of the following is the correct expression for Impedance

Z(s)?

(A)(Ls + R)/(LCs 2 + 1)

(B) (LCs + R)/(LCs 2 + 1)

(C)(RLCs + R)/(LCs 2 + 1)

(D) (RLCs 2 + R + Ls)/(LCs 2 + 1)

Answer : [D] (RLCs 2 + R + Ls)/(LCs 2 + 1)

10. Let f (t) is any function, and then lim t→0 f t = lim t→∞ f(t) will be satisfied for which of

the following function?

(A) u(t)

(B) δ(t)

(C) Sin 2t

(D) Cos 2t

(E) Sin2t + Cos 2t

(F) None

Answer : [A] u(t)