$A$ solenoid is at a potential difference of $60\, V$ and the current flowing through it is $15\, A$. The resistance of the coil will be ............ $\Omega$.

The current $(I)$ and voltage $(V)$ graphs for a given metallic wire at two different temperatures $T_1$ and $T_2$ are shown in the figure. It is concluded that

For a wire,$\frac{R}{l} = \frac{1}{2} \, \Omega/cm$ and the length of the wire is $l = 5 \, cm$. If a potential difference of $1 \, V$ is applied across it,the current through the wire will be: $(R = \text{Resistance})$ (in $A$)

$E$ is the electric field inside a conductor whose material has conductivity $\sigma$ and resistivity $\rho$. The current density inside the conductor is $J$. The correct form of Ohm's law is

The resistance of a discharge tube is

State and explain Ohm's law.