CBSE Class 12 · 2013 · Electromagnetic InductionVery Short Answer

WhatsApp Email

How does the mutual inductance of a pair of coils change when
(i) the distance between the coils is decreased, and
(ii) the number of turns in the coils is decreased?

Answer: (i) Mutual inductance increases.
(ii) Mutual inductance decreases.

Solution

Mutual inductance measures the flux one coil links in the other per unit current, and

M \propto N_{1} N_{2}

while also growing as the coils are brought closer (better flux linkage).
(i) Decreasing the separation improves the flux linkage, so

M

increases.
(ii) Decreasing the number of turns lowers both the flux set up and the flux linked, so

M

decreases.

CBSE Class 12 Board · 2013 · Subjective

Practise more: all CBSE board PYQs on Electromagnetic Induction →

More board questions on Electromagnetic Induction

A coil of area of cross-section $0.5 m^{2}$ is placed in a magnetic field acting normally to its plane. The field varies as $B = 0.5 t^{2} + 2 t$ , where $B$ is in tesla and $t$ in seconds. The emf induced in the coil at $t = 1 s$ is
CBSE 2024View solution →
(a) State Lenz's law. In a closed circuit, the induced current opposes the change in magnetic flux that produced it, in accordance with the law of conservation of energy. Justify this.
(b) A metal rod of length $2 m$ is rotated with a frequency of $60 rev/s$ a …
CBSE 2024View solution →
(i) Define the coefficient of self-induction and obtain an expression for the self-inductance of a long solenoid of length $ℓ$ , area of cross-section $A$ , having $N$ turns.
(ii) Calculate the self-inductance of a coil using the data obtained when an AC source of frequency …
CBSE 2023View solution →
(i) With the help of a labelled diagram, describe the principle and working of an AC generator. Hence obtain an expression for the instantaneous value of the emf generated.
(ii) The coil of an AC generator consists of $100$ turns of wire, each of area $0.5 m^{2}$ . The r …
CBSE 2023View solution →
Consider the experimental set-up shown in the figure. This jumping-ring experiment is a demonstration of simple laws of physics: a conducting non-magnetic ring is placed over the vertical core of a solenoid, and when current is passed through the solenoid, the ring is thrown off. …
CBSE 2023View solution →
The number of turns of a solenoid is doubled without changing its length and area of cross-section. The self-inductance of the solenoid will become ____ times.
CBSE 2020View solution →