This set of Network Theory Multiple Choice Questions & Answers (MCQs) focuses on “Thevenin’s Theorem”.

1. Consider the circuit shown below. Find the equivalent Thevenin’s voltage between nodes A and B.

a) 8

b) 8.5

c) 9

d) 9.5

View Answer

Explanation: The thevenin’s voltage is equal to the open circuit voltage across the terminals AB that is across 12Ω resistor. V

_{th}= 10×12/14 = 8.57V.

2. In the circuit shown above in question 1 find the thevenin’s resistance between terminals A and B.

a) 1

b) 2

c) 1.7

d) 2.7

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Explanation: The resistance into the open circuit terminals is equal to the thevenin’s resistance => R

_{th}= (12×2)/14 = 1.71Ω.

3. In the figure shown above in question 1 find the current flowing through 24Ω resistor.

a) 0.33

b) 0.66

c) 0

d) 0.99

View Answer

Explanation: The equivalent thevenin’s model of the circuit shown is

I=8.57/(2.4+1.71)=0.33A.

4. Determine the equivalent thevenin’s voltage between terminals A and B in the circuit shown below.

a) 0.333

b) 3.33

c) 33.3

d) 333

View Answer

Explanation: Let us find the voltage drop across terminals A and B. 50-25=10I+5I => I=1.67A. Voltage drop across 10Ω resistor = 10×1.67=16.7V. So, V

_{th}=V

_{AB}=50-V=50-16.7=33.3V.

5. Find the equivalent thevenin’s resistance between terminals A and B in the circuit shown above in question 4.

a) 333

b) 33.3

c) 3.33

d) 0.333

View Answer

Explanation: To find R

_{th}, two voltage sources are removed and replaced with short circuit. The resistance at terminals AB then is the parallel combination of the 10Ω resistor and 5Ω resistor => R

_{th}=(10×5)/15=3.33Ω.

6. Determine the equivalent thevenin’s voltage between terminals A and B in the circuit shown below.

a) 5

b) 15

c) 25

d) 35

View Answer

Explanation: Current through 3Ω resistor is 0A. The current through 6Ω resistor = (50-10)/(10+6)=2.5A. The voltage drop across 6Ω resistor = 25×6=15V. So the voltage across terminals A and B = 0+15+10 = 25V.

7. Find the equivalent thevenin’s resistance between terminals A and B in the circuit shown above in question 6.

a) 6

b) 6.25

c) 6.5

d) 6.75

View Answer

Explanation: To find R

_{th}, two voltage sources are removed and replaced with short circuit => R

_{th}=(10×6)/(10+6)+3=6.75Ω.

8. Determine the equivalent thevenin’s voltage between terminals ‘a’ and ‘b’ in the circuit shown below.

a) 0.7

b) 1.7

c) 2.7

d) 3.7

View Answer

Explanation: The voltage at terminal a is V

_{a}=(100×6)/16=37.5V, The voltage at terminal b is V

_{b}=(100×8)/23=34.7V. So the voltage across the terminals ab is V

_{ab}=V

_{a}-V

_{b}=37.5-34.7=2.7V.

9. Find the equivalent thevenin’s resistance between terminals A and B in the circuit shown above in question 8.

a) 6

b) 7

c) 8

d) 9

View Answer

Explanation: To find R

_{th}, two voltage sources are removed and replaced with short circuit => R

_{ab}=(6×10)/(6+10)+(8×15)/(8+15)=8.96≅9V.

10. Find the current through 5Ω resistor in the circuit shown above in question 8.

A) 0.1

b) 0.2

c) 0.3

d) 0.4

View Answer

Explanation: The Equivalent Thevenin’s circuit for the circuit shown above is

I=2.7/(8.96+5)=0.193A≅0.2A.

**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__.