11. In the Superposition theorem, while considering a source, all other voltage sources are?
A. open circuited
B. short-circuited
C. change its position
D. removed from the circuit
Answer: B
In the Superposition theorem, while considering a source, all other voltage sources are short-circuited. This theorem is valid for linear systems.
12. In the Superposition theorem, while considering a source, all other current sources are?
A. short-circuited
B. change its position
C. open circuited
D. removed from the circuit
Answer: C
In the Superposition theorem, while considering a source, all other current sources are open-circuited. The superposition theorem is not valid for power responses. It is applicable only for computing voltage and current responses.
13. In the circuit shown, find the current through a 4Ω resistor using the Superposition theorem.
A. 4
B. 5
C. 6
D. 7
Answer: B
Considering the voltage source 20V, 5A current source is open-circuited.
Now current through 3Ω resistor is
20/(5 + 4) = 2.22A.
Now considering the current source 5A, the 20V voltage source is short-circuited.
No current through a 3Ω resistor is
5 × 5/(4 + 5) = 2.78A.
Now finally the current through 3Ω resistor is 2.22 + 2.78 = 5A.
14. Consider the circuit shown below. Find the voltage across 2Ω resistors due to the 10V voltage source using the Superposition theorem.
A. 0
B. 1
C. 2
D. 3
Answer: B
Short-circuiting 20V source, open circuiting 2A source,
The voltage at node A is
(V-10)/10+V/20+V/7=0 => V=3.41V.
=> The voltage across the 2Ω resistor is V/(7)×2=0.97V≅1V.
15. Find the voltage across a 2Ω resistor due to the 20V source in the following figure.
A. − 2.92
B. 2.92
C. 1.92
D. − 1.92
Answer: A
Short circuiting 10V source, open circuiting 2A source,
The voltage at node A is
(V − 20)/7 + V/20 + V/10 = 0 = > V = 9.76V.
Now the voltage across 2Ω resistor is (V − 20)/7×2 = − 2.92V.
16. Find the voltage across 2Ω resistors due to the 2A source in the following figure.
A. − 1
B. 1
C. 1.46
D. − 1.46
Answer: D
Short-circuiting both 10V, and 20V sources,
The current through 2Ω resistor is
2× 5/(5 + 8.67) = 0.73A.
The voltage across the 2Ω resistor is − 0.73×2 = − 1.46V.
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17. In the figure shown below. Find the voltage across 2Ω resistors due to all sources using the Superposition theorem.
A. 3.41
B. − 3.41
C. 3.14
D. − 3.14
Answer: B
The algebraic sum of all the voltages obtained by considering individual sources is the voltage across a 2Ω resistors.
V = 0.97 − 2.92 − 1.46 = − 3.41V.
18. Find the voltage across a 2Ω resistor due to the 20V source in the circuit shown below.
A. 1
B. 1.5
C. 2
D. 2.5
Answer: B
The voltage at node A in the figure is
(V − 20)/20 + (V − 10)/10 + V/2 = 0 = > V = 3.07V.
Now short circuiting 10V source,
(V − 20)/20 + V/2 + V/10 = 0 = > V = 1.5V.
19. Find the voltage across a 2Ω resistors due to a 20V source in the following circuit.
A. 0.5
B. 0
C. 1
D. 1.5
Answer: D
The voltage at node A is
(V − 20)/20 + (V − 10)/10 + V/2 = 0 = > V = 3.07V.
Now short circuiting 20V source,
(V − 10)/10 + V/20 + V/2 = 0 = > V = 1.5V.
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20. Find the voltage across 2Ω resistors in the circuit shown below using the Superposition theorem.
A. 1
B. 2
C. 3
D. 4
Answer: C
The voltage across 2Ω resistors is the algebraic sum of the voltages obtained by considering individual sources. V = 1.5 + 1.5 = 3V.
21. The Superposition Theorem is not applicable for _________
A. Power calculation
B. Voltage calculation
C. Current Calculation
D. Both Voltage and Current calculation
Answer: A
The Superposition Theorem is not applicable for Power calculation because for power, the calculations involve either the product of voltage and current or the square of current or the square of the voltage thus making them non-linear operations. Hence they cannot be calculated using Superposition Theorem.
22. In the superposition theorem when we consider one voltage source, all the other voltage sources are ___________
A. Shorted
B. Removed
C. Undisturbed
D. Opened
Answer: A
To determine the contribution of each source in the case of the Superposition Theorem, we short circuit all the other voltage sources (which are independent) and open circuit all the independent current sources (which are independent).
