The unit of inductance is

The current flowing through an inductance coil of self-inductance $6 \text{ mH}$ at different time instants is as shown. The emf induced between $t=20 \text{ s}$ and $t=40 \text{ s}$ is nearly

In a coil,current falls from $5\, A$ to $0\, A$ in $0.2\, s$. If an average $emf$ of $150\, V$ is induced,then the self-inductance of the coil is.....$H$

The self-inductance of a coil is $L$. Keeping the length and area the same,the number of turns in the coil is increased to four times. The self-inductance of the coil will now be

The length of a wire required to make a solenoid of length $l$ and self-induction $L$ is

Two different coils have self-inductance $3L$ and $L$. The current in both the coils is increased at the same constant rate. At a certain instant of time, the power given to the two coils is same. At that time, there was current and voltage induced in the two coils. At the same instant, the ratio of energy stored in the first coil to that in the second coil is