# Factors Affecting Inductance MCQ [Free PDF] – Objective Question Answer for Factors Affecting Inductance Quiz

1. As the number of turns in the coil increases, what happens to the inductance of the coil?

A. Increases
B. Decreases
C. Remains the same
D. Becomes zero

Inductance is directly proportional to the square of the number of turns in the coil, hence as the number of turns increases, inductance also increases.

2. What happens to the inductance when the magnetic field strength decreases?

A. Increases
B. Decreases
C. Remains the same
D. Becomes zero

Inductance is directly proportional to the magnetic field strength in the coil, hence as the magnetic field strength decreases, inductance decreases.

3. 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

ϕ is directly proportional to i.

Φ = Li

where

L is the constant of proportionality

So, when the current gets double ϕ also becomes double keeping L the same.

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

A. The variation of flux is no longer proportional to the variation of current
B. Current does not exist in the coil
C. Flux does not exist in the coil
D. The value of the current is too large to measure

When a coil is wrapped around a ferromagnetic core, it is difficult to determine the inductance because the variation of flux is no longer proportional to the variation of the current.

5. What happens to the inductance as the area of the cross-section of the coil increases?

A. Increases
B. Decreases
C. Remains the same
D. Becomes zero

L = µ0 × N2 × A/l,

hence as the area of cross section A increases, the inductance also increases.

6. What happens to the inductance as the length of the magnetic circuit increases?

A. Increases
B. Decreases
C. Remains the same
D. Becomes zero

L = µ0 × N2 × A/l

hence as the length of the magnetic circuit l increases, the inductance decreases.

7. If the current changes from 20A to 10A in 5 seconds and the value of inductance is 1H, calculate the emf induced.

A. 8V
B. 6V
C. 4V
D. 2V

We know that:

emf = L(i2 − i1)/t

Substituting the values from the question we get emf = 2V.

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

A. Increases
B. Decreases
C. Remains the same
D. Becomes zero

When a ferromagnetic core is introduced into an inductor, its flux increases because the number of magnetic field lines increases due to the introduction of the magnetic field within the coil.

9. What happens to the current when a ferromagnetic material is introduced within an inductor?

A. Increases
B. Decreases
C. Remains the same
D. Becomes zero

When a ferromagnetic is introduced within an inductor, the current remains fairly constant. This is because the current does not depend on the magnetic field.

10. 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