$A$ graph of magnetic flux $(\phi)$ versus current $(I)$ is shown for $4$ different inductors $P, Q, R, S$. The minimum value of inductance is for inductor:

The current in a coil of inductance $5\, H$ decreases at the rate of $2\, A/s$. The induced $e.m.f.$ is....$V$

$A$ coil is wound on a core of rectangular cross-section. If all the linear dimensions of the core are increased by a factor of $2$ and the number of turns per unit length of the coil remains the same, the self-inductance increases by a factor of (Assume, permeability is same).

Self-induction of a solenoid cannot be increased by

The total number of turns and cross-section area in a solenoid are fixed. However,its length $L$ is varied by adjusting the separation between windings. The inductance of the solenoid will be proportional to

To manufacture a solenoid of length $1 \,m$ and inductance $1 \,mH$, the length of thin wire required is (cross-sectional diameter of a solenoid is considerably less than the length).