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

Two circular coils can be arranged in any of the three situations shown in the figure. Their mutual inductance will be

An electric current $i_1$ can flow either direction through loop $(1)$ and induced current $i_2$ in loop $(2)$. Positive $i_1$ is when current is from $'a'$ to $'b'$ in loop $(1)$ and positive $i_2$ is when the current is from $'c'$ to $'d'$ in loop $(2)$ In an experiment, the graph of $i_2$ against time $'t'$ is as shown below Which one $(s)$ of the following graphs could have caused $i_2$ to behave as give above.

Two circuits have mutual inductance of $0.1\, H$. What average $e.m.f$. is induced in one circuit when the current in the other circuit changes from $0$ to $20\, A$ in $0.02$ $s$......$V$

There are two coils $\mathrm{A}$ and $\mathrm{B}$ separated by some distance. If a current of $2\mathrm{A}$ flows through $\mathrm{A}$, a magnetic flux of $10^{-2}\mathrm{Wb}$ passes through $\mathrm{B}$ ( no current through $\mathrm{B}$ ). If no current passes through $\mathrm{A}$ and a current of $1\mathrm{A}$ passes through $\mathrm{B}$, what is the flux through $\mathrm{A}$ ?

Two coil $A$ and $B$ have coefficient of mutual inductance $M = 2H$. The magnetic flux passing through coil $A$ changes by $4$ Weber in $10$ seconds due to the change in current in $B$. Then