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......$V$

If a change in current of $0.01\, A$ in one coil produces a change in magnetic flux of $1.2 \times {10^{ - 2}}\,Wb$ in the other coil, then the mutual inductance of the two coils in henries is.....$H$

$(a)$ Obtain an expression for the mutual inductance between a long straight wire and a square loop of side $a$ as shown in Figure.

$(b)$ Now assume that the straight wire carries a current of $50\; A$ and the loop is moved to the right with a constant velocity, $v=10 \;m / s$ Calculate the induced $emf$ in the loop at the instant when $x=0.2\; m$ Take $a=0.1\; m$ and assume that the loop has a large resistance.

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

The mutual inductance between two coils is $1.25$ $henry$. If the current in the primary changes at the rate of $80$ $ampere/second,$ then the induced $e.m.f$ in the secondary is......$V$

Two conducting circular loops $A $and $B$ are placed in the same plane with their centres coinciding as shown in figure. The mutual inductance between them $1$s: