250+ TOP MCQs on Open Circuit Impedence(Z) Parameters and Answers

Network Theory Question Bank on “Open Circuit Impedence(Z) Parameters”.

1. Two ports containing no sources in their branches are called?
A. active ports
B. passive ports
C. one port
D. three port

Answer: B
Clarification: Two ports containing no sources in their branches are called passive ports; among them are power transmission lines and transformers.

2. Two ports containing sources in their branches are called?
A. three port
B. one port
C. passive ports
D. active ports

Answer: D
Clarification: Two ports containing sources in their branches are called active ports. A voltage and current is assigned to each of the two ports.

3. In determining open circuit impedance parameters, among V₁, V₂, I₁, I₂, which of the following are dependent variables?
A. V₁ and V₂
B. I₁ and I₂
C. V₁ and I₂
D. I₁ and V₂

Answer: A
Clarification: In determining open circuit impedance parameters, among V₁, V₂, I₁, I₂; V₁ and V₂ are dependent variables and I₁, I₂ are independent variables i.e., dependent variables depend on independent variables.

4. In determining open circuit impedance parameters, among V₁, V₂, I₁, I₂, which of the following are independent variables?
A. I₁ and V₂
B. V₁ and I₂
C. I₁ and I₂
D. V₁ and V₂

Answer: C
Clarification: In determining open circuit impedance parameters, among V₁, V₂, I₁, I₂; I₁ and I₂ are independent variables and V₁, V₂ are dependent variables. Independent variables are the variables that do not depend on any other variable.

5. Which of the following expression is true in case of open circuit parameters?
A. V₁ = Z₁₁ V₁ + Z₁₂ I₂
B. V₁ = Z₁₁I₁ + Z₁₂ V₂
C. V₁ = Z₁₁I₁ + Z₁₂ I₂
D. V₂ = Z₁₁I₁ + Z₁₂ I₂

Answer: C
Clarification: The expression relating the open circuit parameters Z₁₁, Z₁₂ and currents I₁, I₂ and voltage V₁ is V₁ = Z₁₁I₁ + Z₁₂ I₂.

6. Which of the following expression is true in case of open circuit parameters?
A. V₂ = Z₂₁I₂ + Z₂₂ I₂
B. V₂ = Z₂₁I₁ + Z₂₂ I₂
C. V₁ = Z₂₁I₂ + Z₂₂ I₂
D. V₁ = Z₂₁I₁ + Z₂₂ I₂

Answer: B
Clarification: The expression relating the currents I₁, I₂ and voltage V₁ and open circuit parameters Z₂₁, Z₂₂ is V₂ = Z₂₁I₁ + Z₂₂ I₂.

7. Find the Z – parameter Z₁₁ in the circuit shown below.

A. 1
B. 1.5
C. 2
D. 2.5

Answer: D
Clarification: For determining Z₁₁, the current I₂ is equal to zero. Now we obtain Z_eq as 1 + (6×2)/(6+2)=2.5Ω. So, Z₁₁ = 2.5Ω.

8. The value of Z₂₁ in the circuit shown below?

A. 0
B. 1
C. 2
D. 3

Answer: B
Clarification: V₂ is the voltage across the 4Ω impedance. The current through 4Ω impedance is I₁/4. And V₂ = (I₁/4) x 4 = I₁. So, Z₂₁ = 1Ω.

9. Find the value of Z₁₂ in the circuit shown below.

A. 3
B. 2
C. 1
D. 0

Answer: C
Clarification: The current through vertical 2Ω resistor is = I₂/2. So, V₁ = 2 x (I₂/2). On solving and substituting we get Z₁₂ = 1Ω.

10. Determine the value of Z₂₂ in the circuit shown below.

A. 0
B. 1
C. 2
D. 3

Answer: C