Basic Electrical Engineering Mock Test 7

10%

Question 1 of 10

1. When a ferromagnetic core is inserted into an inductor, what happens to the flux linkage?

Remains the same

Increases

Becomes zero

Decreases

Question 1 of 10

Question 2 of 10

2. The B/H ratio is not constant for ________

Non-magnetic materials

Paramagnetic materials

Diamagnetic materials

Ferromagnetic materials

Question 2 of 10

Question 3 of 10

3. What is the expression for voltage in the given circuit?

V=60e^-0.5t

V=30e^-0.5t

V=60e^-2t

V=30e^-2t

Question 3 of 10

Question 4 of 10

4. If the current changes from 5A to 3A in 2 seconds and the inductance is 10H, calculate the emf.

10V

15V

20V

Question 4 of 10

Question 5 of 10

5. A laminated steel ring is wound with 200 turns. When the magnetizing current varies between 5 and 7 A, the magnetic flux varies between 760 and 800 Wb. Calculate the inductance of the coil.

4 H

0.004 H

4000H

40H

Question 5 of 10

Question 6 of 10

6. Calculate the inductance in an inductive circuit whose time constant is 2s and the resistance is 5 ohm.

20H

10H

15H

Question 6 of 10

Question 7 of 10

7. 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.

Question 7 of 10

Question 8 of 10

8. What is the time constant of an inductive circuit?

R/L

1/LR

L/R

Question 8 of 10

Question 9 of 10

9. When the coil is wrapped around a ferromagnetic core, why is it difficult to determine the inductance?

Current does not exist in the coil

The variation of flux is no longer proportional to the variation of current

The value of current is too large to measure

Flux does not exist in the coil

Question 9 of 10

Question 10 of 10

10. What is MMF?

Magnetic Motion Force

Magnetic Machine Force

Magnetomotive Force

Magnetomotion Force

Question 10 of 10