This set of Network Theory Multiple Choice Questions & Answers (MCQs) focuses on “Terminated Two-Port Network”.

1. Calculate the Z –parameter Z_{11} in the circuit shown below.

a) 1.5

b) 2.5

c) 3.5

d) 4.5

View Answer

Explanation: The Z –parameter Z

_{11}is V

_{1}/I

_{1}, port 2 is open circuited. V

_{1}= (1+1.5)I

_{1}=> V

_{1}/I

_{1}= 2.5 and on substituting, we get Z

_{11}= 2.5Ω.

2. Determine the Z-parameter Z_{12} in the circuit shown in question 1.

a) 1

b) 2

c) 3

d) 4

View Answer

Explanation: The Z-parameter Z

_{12}is V

_{2}/I

_{1}|I

_{2}=0. On open circuiting port 2 we obtain the equation, V

_{1}= (1.5) I

_{2}=> V

_{1}/I

_{1}= 1.5. On substituting we get Z

_{12}= 1.5Ω.

3. Determine the Z-parameter Z_{21} in the circuit shown in question 1.

a) 4

b) 3

c) 2

d) 1

View Answer

Explanation: The Z-parameter Z

_{21}is V

_{2}/I

_{1}|I

_{2}=0. On open circuiting port 2, we get V

_{2}= (1.5)I

_{1}=> V

_{2}/I

_{1}= 1.5. On substituting we get Z

_{21}= 1.5Ω.

4. Determine the Z-parameter Z_{22} in the circuit shown in question 1.

a) 1

b) 3

c) 2

d) 4

View Answer

Explanation: The Z-parameter Z

_{21}is V

_{2}/I

_{2}|I

_{1}=0. This parameter is obtained by open circuiting port 1. So we get V

_{2}= ((2+2)||4)I

_{2}=> V

_{2}= 2(I

_{2}) => V

_{2}/I

_{2}= 2. On substituting Z

_{21}= 2Ω.

5. Find the value of V_{1}/I_{1} in the circuit shown in question 1.

a) 1.25

b) 2.25

c) 3.25

d) 4.25

View Answer

Explanation: We have the relation V

_{1}/I

_{1}=Z

_{11}– Z

_{12}Z

_{21}/(Z

_{L}+Z

_{21}) and Z

_{L}is the load impedance and is equal to 2Ω. On solving V

_{1}/I

_{1}=2.5-1/(2+2)=2.25Ω.

6. Determine the input impedance of the network shown in question 1.

a) 4.25

b) 3.25

c) 2.25

d) 1.25

View Answer

Explanation: From the figure by inspection we can say that the source resistance is 1Ω. So Z

_{in}= (V

_{1}/I

_{1}) + Source resistance. We had V

_{1}/I

_{1}= 2.25. On substituting Z

_{in}=1+2.25=3.25Ω.

7. Determine the value of source admittance in the circuit shown below.

a) 1

b) 2

c) 3

d) 4

View Answer

Explanation: From the figure the value of the admittance parallel to the current source is 1 mho and this is the value of source admittance. So Y

_{s}= 1 mho.

8. Find the value of I_{2}/V_{2} in the circuit shown in question 7.

a) 7/6

b) 6/7

c) 7/12

d) 12/7

View Answer

Explanation: The relation between I

_{2}/V

_{2}and Y-parameters is

I

_{2}/V

_{2}=(5/8×1+5/8×1/2-1/16)/(1+1/2)=7/12 mho.

9. The value of the Y-parameter Y_{22} in the circuit shown in question 7.

a) 12/7

b) 6/7

c) 7/6

d) 7/12

View Answer

Explanation: The relation between Y

_{22}and I

_{2}/V

_{2}is Y

_{22}= I

_{2}/V

_{2}. We have the relation I

_{2}/V

_{2}= (Y

_{22}Y

_{s}+Y

_{22}Y

_{11}-Y

_{21}Y

_{12})/(Y

_{s}+Y

_{11}). On substituting their values in the equation we get Y

_{22}= 7/12 mho.

10. The value of the Z-parameter Z_{22} in the circuit shown in question 7.

a) 6/7

b) 7/12

c) 12/7

d) 7/6

View Answer

Explanation: The Z-parameter Z

_{22}is inverse of the Y-parameter Y

_{22}i.e., Z

_{22}= 1/Y

_{22}. We got Y

_{22}= 7/12. So on substituting we get Z

_{22}= 12/7 mho.

**Sanfoundry Global Education & Learning Series – Network Theory.**

To practice all areas of Network Theory, __here is complete set of 1000+ Multiple Choice Questions and Answers__.