Two conducting circular loops of radii $R_{1}$ and $\mathrm{R}_{2}$ are placed in the same plane with their centres coinciding. If $R_{1}>>R_{2}$, the mutual inductance $M$ between them will be directly proportional to:

Two coils $A$ and $B$ having turns $300$ and $600$ respectively are placed near each other, on passing a current of $3.0$ ampere in $A$, the flux linked with A is $1.2 \times {10^{ - 4}}\,weber$ and with $B$ it is $9.0 \times {10^{ - 5}}\,weber$. The mutual inductance of the system is

Two circuits have coefficient of mutual induction of $0.09$ $henry$. Average $e.m.f$. induced in the secondary by a change of current from $0$ to $20$ $ampere$ in $0.006$ $second$ in the primary will be......$V$

A circular loop of radius $0.3\, cm$ lies parallel to a much bigger circular loop of radius $20 \,cm$. The centre of the small loop on the axis of the bigger loop. The distance between their centres is $15\, cm$. If a current of $20\, A$ flows through the smaller loop, then the flux linked with bigger loop is

There are $10$ turns in coil $M$ and $15$ turns in coil $N$ . If a current of $2\ A$ is passed through coil $M$ then the flux linked with coil $N$ is $1.8 × 10^{-3}\ Wb$ . If a current of $3\ A$ is passed through coil $N$ then flux linked with coil $M$ is

Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross-sectional area $A = 10\ cm^2$ and length$= 20\ cm$. If one of the solenoid has $300$ turns and the other $400$ turns, their mutual inductance is

$\mu_{0}=4 \pi \times 10^{-7} \;TmA ^{-1}$