The self-inductance of a straight conductor is

The $SI$ unit of self-inductance is:

The inductance of a close-packed coil of $400$ turns is $8 \, mH$. $A$ current of $5 \, mA$ is passed through it. The magnetic flux through each turn of the coil is

Two coils have self-inductance $L_1$ and $L_2$. The current through them is increasing at a constant rate. If the power dissipated in both the coils is the same, then the ratio of energy stored in the coil having inductance $L_1$ to that in $L_2$ is

$A$ solenoid of length $l$ metre has self-inductance $L$ henry. If the number of turns is doubled,its self-inductance becomes:

$A$ current of $0.5 \ A$ is passed through the winding of a long solenoid having $400$ turns. The magnetic flux linked with each turn is $3 \times 10^{-3} \ Wb$. The self-inductance of the solenoid is: (in $H$)