250+ TOP MCQs on Short Circuit Admittance(Y) Parameters and Answers

Network Theory Multiple Choice Questions on “Short Circuit Admittance(Y) Parameters”.

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

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

3. Which of the following expression is true in case of short circuit parameters?
A. I₁ = Y₁₁ V₁ + Y₁₂ V₂
B. I₁ = Y₁₁ I₁ + Y₁₂ V₂
C. V₁ = Y₁₁ I₁ + Y₁₂ V₂
D. V₁ = Y₁₁ V₁ + Y₁₂ V₂

Answer: A
Clarification: The expression relating the short circuit parameters Y₁₁, Y₁₂ and voltages V₁, V₂ and current is I₁, is I₁ = Y₁₁ V₁ + Y₁₂ V₂.

4. Which of the following expression is true in case of short circuit parameters?
A. I₂ = Y₂₁I₁ + Y₂₂ I₂
B. V₂ = Y₂₁I₁ + Y₂₂ V₂
C. I₂ = Y₂₁V₁ + Y₂₂ V₂
D. I₂ = Y₂₁V₁ + Y₂₂ I₂

Answer: C
Clarification: The expression relating the voltages V₁, V₂ and current is I₂ and short circuit parameters Y₁₁, Y₁₂ is I₂ = Y₂₁V₁ + Y₂₂V₂.

5. The parameters Y₁₁, Y₁₂, Y₂₁, Y₂₂ are called?
A. Open circuit impedance parameters
B. Short circuit admittance parameters
C. Inverse transmission parameters
D. Transmission parameters

Answer: B
Clarification: The parameters Y₁₁, Y₁₂, Y₂₁, Y₂₂ are called short circuit admittance parameters also called network functions as they are obtained by short circuiting port 1 or port 2.

6. Find the Y – parameter Y₁₁ in the circuit shown below.
A. 2
B. 3/2
C. 1
D. 1/2

Answer: D
Clarification: After short circuiting b-b’, the equation will be V₁ = (I₁) x 2. We know Y₁₁ = I₁/V₁. From the equation we get I₁/V₁ = 2. On substituting we get Y₁₁ = 2 mho.

7. Find the Y – parameter Y₂₁ in the circuit shown below.
A. -1/4
B. 1/4
C. 1/2
D. -1/2

Answer: A
Clarification: After short circuiting b-b’, the equation will be -I₂=I₁ × 2/4=I₁/2 and -I₂ = V₁/4 and on solving and substituting we get Y₂₁ = I₂/V₁=-1/4 mho.

8. Find the Y – parameter Y₂₂ in the circuit shown below.
A. 3/8
B. 5/8
C. 7/8
D. 9/8

Answer: B
Clarification: On short circuiting a-a’, we get Z_eq = 8/5 Ω. V₂=I₂× 8/5. We know Y₂₂ = I₂/V₂. We got I₂/V₁ = 5/8. ON substituting we get Y₂₂ = 5/8 mho.

9. Find the Y – parameter Y₁₂ in the circuit shown below.
A. 1/2
B. -1/2
C. -1/4
D. 1/4

Answer: C
Clarification: Short circuiting a-a’, -I₁ = 2/5 I₂ and I₂ = 5 V₂/8. On solving -I₁ = 2/5×5/8 V₂ = V₂/4. We know Y₁₂ = I₁/V₂. We got I₁/V₂ = -1/4. So the value of Y₁₂ will be -1/4 mho.

10. Which of the following equation is true in the circuit shown below?
A. I₁=0.5(V₁)+0.25(V₂)
B. I₁=0.25(V₁)+0.625(V₂)
C. I₁=-0.25(V₁)+0.625(V₂)
D. I₁=0.5(V₁)-0.25(V₂)

Answer: D
Clarification: We got the admittance parameters as Y₁₁ = 0.5, Y₁₂ = -0.25, Y₂₁ = -0.25, Y₂₂ = 0.625. So the equations in terms of admittance parameters is I₁=0.5(V₁)-0.25(V₂) and I₂=-0.25(V₁)+0.625(V₂).