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.

What is the coefficient of mutual inductance when the magnetic flux changes by $2 \times {10^{ - 2}}\,Wb$ and change in current is $0.01\,A$......$henry$

The area of its cross-section is $1.2 \times {10^{ - 3}}{m^2}$. Around its central section, a coil of $300$ turns is wound. If an initial current of $2A$ in the solenoid is reversed in $0.25\, sec$, then the $e.m.f$. induced in the coil is

Mutual inductance of two coils can be increased by

An $e.m.f.$ of $100\,millivolts$ is induced in a coil when the current in another nearby coil becomes $10\, ampere$ from zero in $0.1\,second$ . The coefficient of mutual induction between the two coils will be.....$millihenry$

Give two definitions of mutual inductance, give its units and write factors on which its value depends.