Basic Electrical MCQs Part-6

Basic Electrical 

1. The maximum power that a 12 V d.c. source with an internal resistance of 2 ohm can supply to a resistive load is_______.

a. 48 W

b. 36 W

c. 18 W

d. 12 W

 

2. In order to apply superposition theorem, it is necessary that the network be only________.

a. Linear and time-variant

b. Linear

c. Time-invariant and reciprocal

d. Linear and reciprocal

 

3. If all the elements in a particular network are linear, then the superposition theorem would hold, when the excitation is______.

a. An impulse

b. AC or DC

c. AC only

d. DC only

 

4. Which of the following theorems is applicable for both linear and non-linear circuits ?

a. Norton's

b. Thevenin's

c. Superposition

d. None of these

 

5. Consider the following statements about Norton's equivalent of acircuit across a given two load terminals:

1. Norton's equivalent resistance is the same as Thevenin's equivalent resistance R_th.

2. Norton's equivalent is the voltage equivalent of the network.

3. The load is connected in parallel to the Norton's equivalent resistance.

Out of the above statements, which statements hold true?

a. 2 and 3 only

b. 1 only

c. 1 and 3 only

d. 1, 2 and 3

 

6. When the power transferred to the load is maximum, the efficiency is_______.

a. 100%

b. 50%

c. 75%

d. 25%

 

7. For a linear network containing generators and impedances, the ratio of the voltage to the current produced in other loop is the same as the ratio of voltage and current obtained if the positions of the voltage source and the ammeter measuring the current are interchanged.

a. Millman's theorem

b. Norton's theorem

c. Tellegen's theorem

d. Reciprocity theorem

8. Millman's theorem yields equivalent_____.

a. Voltage source

b. Voltage or current source

c. Current source

d. Impedance or resistance

 

9. If the source impedance is inductive, for maximum transfer of power from the source the load, the load should be______.

a. Complex conjugate of complex source impedance

b. Resistive

c. Capacitive

d. None of the above

 

10. Assertion(A) : Norton's theorem is called dual of the thevenin's theorem.

Reason(R) : If the Thevenin's equivalent voltage source is converted to an equivalent current source, the Norton's equivalent is obtained.

a. A is false but R is true

b. A is true but R is false

c. Both A and R are true but R is not the correct explanation of A

d. Both A and R are true and R is the correct explanation of A

 

11. Assertion(A) : In any active network, maximum power transfer to the load takes place when the load impedance is equal to an equivalent impedance of the network as viewed from the terminals of the load.

Reason(R) : For finding the maximum power transfer to the load, any network has to be first converted into Thevenin's equivalent across the terminals of the load.

a. A is false but R is true

b. A is true but R is false

c. Both A and R are true but R is not the correct explanation of A

d. Both A and R are true but R is the correct explanation of A

 

12. Assertion(A) : The substitution theorem is very useful in the networks consisting the mutual inductances.

Reason(R) : By the subsititution theorem, the effect ofm utual inductances may be replaced by equivalent dependent sources of the same value.

a. A is false but R is true

b. A is true but R is false

c. Both A and R are true but R is not the correct explanation of A

d. Both A and R are true but R is the correct explanation of A

 

13. Consider the following statements related to Thevenin's theorem:

For the application of Thevenin's theorem

1. The circuit should not conotain non-linear elements.

2. The circuit may contain unilateral or bilateral elements or both

3. There should not be magnetic coupling between the load and circuit, to be replaced by Thevenin's theorem

4. There should not be controlled sources on the load size, controlled sources on the load size, controlled from some other part of the circuit.

Which of the above statements is/are true?

a.1 and 4 only

b. 1, 3 and 4 only

c. 2, 3 and 4 only

d. 1, 2 and 3 only

 

14. Which of the following theorem is applicable to both linear and non-linear netwroks?

a. Substitution theorem

b. Norton's theorem

c. Superposition theorem

d. Thevenin's theorem