Current in a circuit falls from $5.0 \, A$ to $0.0 \, A$ in $0.1 \, s$. If an average $emf$ of $200 \, V$ is induced,give an estimate of the self-inductance of the circuit in $H$.

$A$ current $i$ $A$ flows along an infinitely long straight thin-walled tube. The magnetic induction at any point inside the tube is:

Sensitivity of a potentiometer can be increased by

If one were to apply the Bohr model to a particle of mass $m$ and charge $q$ moving in a plane under the influence of a magnetic field $B$,the energy of the charged particle in the $n^{th}$ level will be:

The pair of gases responsible for acid rain are

Based on the compounds of group $15$ elements, the correct statement($s$) is (are)

$(A)$ $Bi _2 O _5$ is more basic than $N _2 O _5$

$(B)$ $NF _3$ is more covalent than $BiF _3$

$(C)$ $PH _3$ boils at lower temperature than $NH _3$

$(D)$ The $N - N$ single bond is stronger than the $P - P$ single bond