Question

Assertion $\left(A\right)$: When two coils are wound on each other, the mutual induction between the coils in maximum.

Reason $\left(R\right)$: Mutual induction does not depend on the orientation of the coils.

• A. Both $\left(A\right)$ and $\left(R\right)$ are true, and $\left(R\right)$ is the correct explanation of $\left(A\right)$
• B. Both $\left(A\right)$ and $\left(R\right)$ are true, but $\left(R\right)$ is not the correct explanation of $\left(A\right)$
• C. $\left(A\right)$ is true but $\left(R\right)$ is false
• D. $\left(A\right)$ is false but $\left(R\right)$ is true

Answer 1

The correct option is C $\left(A\right)$ is true but $\left(R\right)$ is false

As we know, the coefficient of mutual inductance is,

$M=\frac{\left(\frac{-d{\varphi }_2}{dt}\right)}{\left(\frac{-d{i}_1}{dt}\right)}=\frac{e_2}{\left(\frac{-d{i}_1}{dt}\right)}$

When coils are mounted one over other the flux linkage is maximum, so mutual inductance will be maximum.
Hence, the assertion is correct.

Flux linkage will definitely depend upon the orientation of the coils. So the reason is false.

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(C\right)$ is the correct answer.