In a transformer, the coefficient of mutual inductance between the primary and the secondary coil is $0.2 \,henry$. When the current changes by $5$ $ampere/second$ in the primary, the induced $e.m.f$. in the secondary will be......$V$

A small circular loop of wire of radius $a$ is located at the centre of a much larger circular wire loop of radius $b$. The two loops are in the same plane. The outer loop of radius $b$ carries an alternating current $I = I_0\, cos\, (\omega t)$ . The emf induced in the smaller inner loop is nearly

A solenoid has $2000$ turns wound over a length of $0.3\,m$. The area of cross-section is $1.2\times10^{-3}\,m^2$. Around its central section a coil of $300$ turns is closely wound. If an initial current of $1\,A$ is reversed in $0.25\,s$. Find the emf induced in the coil.......$mV$

What is the mutual inductance of a two-loop system as shown with centre separation l

Two coils have a mutual inductance $0.005\,H$ . The current changes in the first coil The current changes in the first coil according to the equation $I = I_0 sin\,\omega t$ , where $I_0 = 10\,A$ and $\omega  = 100\pi \,rad/s$ . The maximum value of $emf$ in the second coil will be

Two coils of self inductance ${L_1}$ and ${L_2}$ are placed closer to each other so that total flux in one coil is completely linked with other. If $M$ is mutual inductance between them, then $M$ is