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This section includes 109 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
1. |
Calculate the emf induced in an inductor if the inductance is 10H and the current is 2A in 4s. |
A. | 2.5V |
B. | 1.5V |
C. | 3.5V |
D. | 5V |
Answer» E. | |
2. |
Find the coupling coefficient if the Mutual inductance is 20H, the inductance of coil 1 is 2H and the inductance of coil 2 is 8H. |
A. | 5 |
B. | 20 |
C. | 2 |
D. | 8 |
Answer» B. 20 | |
3. |
In an RL series circuit, when the switch is closed and the circuit is complete, what is the response? |
A. | Response does not vary with time |
B. | Decays with time |
C. | Increases with time |
D. | First increases, then decrease |
Answer» C. Increases with time | |
4. |
A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the initial value of the voltage across the inductor. |
A. | 5V |
B. | 10V |
C. | 0 V |
D. | 20V |
Answer» E. | |
5. |
Which, among the following, is the correct formula to find the coupling coefficient? |
A. | k=M/sqrt(L1L2) |
B. | k=M/sqrt(L1²) |
C. | k=M/sqrt(L2²) |
D. | k=M/(L1L2) |
Answer» B. k=M/sqrt(L1²) | |
6. |
A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the value of current 1s after the switch is closed. |
A. | 5.44A |
B. | 4.32A |
C. | 6.56A |
D. | 2.34A |
Answer» C. 6.56A | |
7. |
The charging time constant of a circuit consisting of an inductor is the time taken for the current in the inductor to become __________% of the initial current. |
A. | 33 |
B. | 63 |
C. | 37 |
D. | 36 |
Answer» C. 37 | |
8. |
If the flux linkage in coil 1 is 3Wb and it has 500 turns and the current in coil 2 is 2A, calculate the mutual inductance. |
A. | 750H |
B. | 500H |
C. | 450H |
D. | 900H |
Answer» B. 500H | |
9. |
Mutual inductance between two coupled coils depend on? |
A. | Amount of flux linkage |
B. | Rate of change of flux linkage |
C. | Rate of change of current |
D. | Flux density |
Answer» C. Rate of change of current | |
10. |
Find the time taken for the current in an inductor to change to 2A from 0A if the power in the inductor is 5W. The value of inductance is 10H. |
A. | 1s |
B. | 2s |
C. | 3s |
D. | 4s |
Answer» E. | |
11. |
Find the value of x if the Mutual inductance is x H, the inductance of coil 1 is 2H and the inductance of coil 2 is 8H. The coupling coefficient is 5. |
A. | 10H |
B. | 20H |
C. | 16H |
D. | 15H |
Answer» C. 16H | |
12. |
What is the SI unit of coupling coefficient? |
A. | H |
B. | H¯¹ |
C. | No unit |
D. | H² |
Answer» D. H² | |
13. |
Calculate the resistance in an inductive circuit whose time constant is 2s and the inductance is 10H. |
A. | 7ohm |
B. | 10ohm |
C. | 2ohm |
D. | 5ohm |
Answer» E. | |
14. |
Which, among the following, is the correct expression for mutual inductance? |
A. | M=N2φ2/I2 |
B. | M=N2φ2/I1 |
C. | M=N1φ2/I2 |
D. | M=N1φ1/I1 |
Answer» C. M=N1φ2/I2 | |
15. |
Calculate the power in an inductive circuit if the inductance is 10H, the current flowing in the inductor is 2A in 4s. |
A. | 50W |
B. | 4W |
C. | 5W |
D. | 10W |
Answer» D. 10W | |
16. |
A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the final value of the voltage across the inductor. |
A. | 5V |
B. | 10V |
C. | 0 V |
D. | 20V |
Answer» D. 20V | |
17. |
The types of inductors are ____________ |
A. | Fixed and variable |
B. | Only fixed |
C. | Only variable |
D. | Neither fixed nor variable |
Answer» B. Only fixed | |
18. |
What is the total applied voltage in an inductive circuit? |
A. | V=Ri+Ldi/dt |
B. | V=Ri+di/dt |
C. | V=i+Ldi/dt |
D. | V=R+Ldi/dt |
Answer» B. V=Ri+di/dt | |
19. |
Find the value of x if the Mutual inductance is 20H, the inductance of coil 1 is xH and the inductance of coil 2 is 8H. The coupling coefficient is 5. |
A. | 2H |
B. | 4H |
C. | 6H |
D. | 8H |
Answer» B. 4H | |
20. |
Calculate the inductance in an inductive circuit whose time constant is 2s and the resistance is 5 ohm. |
A. | 10H |
B. | 20H |
C. | 5H |
D. | 15H |
Answer» B. 20H | |
21. |
Calculate the value of stored energy in an inductor if the value of inductance is 20H and 4A of current flows through it. |
A. | 220J |
B. | 150J |
C. | 190J |
D. | 160J |
Answer» E. | |
22. |
For a coil having a magnetic circuit of constant reluctance, the flux is ___________ to the current. |
A. | Directly proportional |
B. | Inversely proportional |
C. | Not related |
D. | Very large compared to |
Answer» B. Inversely proportional | |
23. |
An induced emf is said to be ________ |
A. | Inductive |
B. | Capacitive |
C. | Resistive |
D. | Cannot be determined |
Answer» B. Capacitive | |
24. |
If the resistance in a circuit is 2 ohm and the impedance is 20 ohm, calculate the power factor. |
A. | 1/10 |
B. | 1/20 |
C. | 1/30 |
D. | 1/40 |
Answer» B. 1/20 | |
25. |
What is the time constant of an inductive circuit? |
A. | LR |
B. | R/L |
C. | 1/LR |
D. | L/R |
Answer» E. | |
26. |
If the current changes from 5A to 3A in x sec and inductance is 10H. The emf is 10V, calculate the value of x. |
A. | 2s |
B. | 3s |
C. | 4s |
D. | 5s |
Answer» B. 3s | |
27. |
Find the average current in an inductor if the total current in the inductor is 26A. |
A. | 10A |
B. | 26A |
C. | 13A |
D. | 5A |
Answer» D. 5A | |
28. |
If the current in one coil is steady, what happens to the mutual inductance? |
A. | Zero |
B. | Infinity |
C. | Doubles |
D. | Halves |
Answer» B. Infinity | |
29. |
What is the SI unit of mutual inductance? |
A. | Ohm |
B. | Henry |
C. | Volt |
D. | Siemens |
Answer» C. Volt | |
30. |
If the current in one coil becomes steady, the current in neighbouring coil is? |
A. | Zero |
B. | Infinity |
C. | Doubles |
D. | Halves |
Answer» B. Infinity | |
31. |
For a coil having a magnetic circuit of constant reluctance, if the flux increases, what happens to the current? |
A. | Increases |
B. | Decreases |
C. | Remains constant |
D. | Becomes zero |
Answer» B. Decreases | |
32. |
If the current in a coil having a constant inductance of L henrys grows at a uniform rate, what is the value of the average current? |
A. | I |
B. | I/2 |
C. | I/4 |
D. | 0 |
Answer» C. I/4 | |
33. |
The flux linkage in coil 1 is x and it has 500 turns and the current in coil 2 is 2A, calculate the value of x if the mutual inductance is 750H. |
A. | 1Wb |
B. | 2Wb |
C. | 3Wb |
D. | 4Wb |
Answer» D. 4Wb | |
34. |
Calculate the current in an inductor if the energy stored is 160J and the inductance is 20H. |
A. | 1A |
B. | 2A |
C. | 3A |
D. | 4A |
Answer» E. | |
35. |
What happens to the inductance when the current in the coil becomes double its original value? |
A. | Becomes half |
B. | Becomes four times |
C. | Becomes double |
D. | Remains same |
Answer» E. | |
36. |
If the current changes from 3A to 5A in 2s and the emf is 10V. Calculate the inductance. |
A. | 10H |
B. | 20H |
C. | 30H |
D. | 40H |
Answer» B. 20H | |
37. |
Find voltage across 20H inductor. |
A. | 2V |
B. | 10V |
C. | 12V |
D. | 20V |
Answer» E. | |
38. |
Find voltage across 12H inductor. |
A. | 2V |
B. | 10V |
C. | 12V |
D. | 20V |
Answer» D. 20V | |
39. |
What is the expression for voltage in the given circuit? |
A. | a |
B. | b |
C. | c |
D. | d |
Answer» D. d | |
40. |
Calculate the equivalent inductance between A and B. |
A. | 30H |
B. | 54H |
C. | 44H |
D. | 60H |
Answer» D. 60H | |
41. |
Find voltage across 10H inductor. |
A. | 2V |
B. | 10V |
C. | 12V |
D. | 20V |
Answer» C. 12V | |
42. |
What is the relation between the flux and the magnetizing current when a ferromagnetic core is introduced within the inductor? |
A. | Directly proportional |
B. | Inversely proportional |
C. | Not proportional |
D. | Current is double of flux |
Answer» D. Current is double of flux | |
43. |
Calculate the change in current in an inductor having inductance 4000H, number of turns is 200 and the flux changes from 760 to 800 Wb. |
A. | 2A |
B. | 4A |
C. | 6A |
D. | 8A |
Answer» B. 4A | |
44. |
Calculate the time constant of an inductive circuit having resistance 5 ohm and inductance 10H. |
A. | 2s |
B. | 4s |
C. | 5s |
D. | 0s |
Answer» B. 4s | |
45. |
What happens to the effective inductance when a ferromagnetic core is introduced? |
A. | Increases |
B. | Decreases |
C. | Remains the same |
D. | Becomes zero |
Answer» B. Decreases | |
46. |
Calculate the value of emf in an inductor if the value of inductance is 15H and an average current of 5A flows through it in 10s. |
A. | 15V |
B. | 7.5V |
C. | 10V |
D. | 5.5V |
Answer» C. 10V | |
47. |
What is the energy stored in the magnetic field if the current in a coil has a constant inductance of L henrys grows at a uniform rate? |
A. | LI/2 |
B. | LI²/2 |
C. | L/2I |
D. | L/2I² |
Answer» C. L/2I | |
48. |
A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the value of voltage 1s after the switch is closed. |
A. | 5.4V |
B. | 10.8V |
C. | 0 V |
D. | 2.7V |
Answer» E. | |
49. |
If either the inductance or the rate of change of current is doubled, the induced e.m.f? |
A. | Remains constant |
B. | Becomes zero |
C. | Doubles |
D. | Becomes half |
Answer» D. Becomes half | |
50. |
Initially, when the switch in a series RL circuit is closed, the inductor acts as? |
A. | Open circuit |
B. | Short circuit |
C. | Resistor |
D. | Capacitor |
Answer» B. Short circuit | |