Consider a current in a circuit falls from $6.0 \,A$ to $1.0 \,A$ in $0.2 \,s$. If an average emf of $150 \,V$ is induced by the circuit,then the self inductance of the circuit is (in $\,H$)

In a coil,the current changes from $-2 \,A$ to $+2 \,A$ in $0.2 \,s$ and induces an emf of $0.1 \,V$. The self-inductance of the coil is: (in $\,mH$)

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

$A$ closely wound coil of $100$ turns and of cross-section $1 \,cm^2$ has a coefficient of self-inductance $1 \,mH$. The magnetic induction at the centre of the core of the coil when a current of $2 \,A$ flows in it will be (in $Wb/m^2$):

An average induced emf of $0.5 \,V$ appears in a coil when the current in it is changed from $10 \,A$ in one direction to $10 \,A$ in the opposite direction in $0.8 \,s$. The self-inductance of the coil is: (in $\,mH$)

Write down the formula for the self-inductance of a very long solenoid.