The voltage of clouds is $4 \times 10^6 \, V$ with respect to the ground. In a lightning strike lasting $100 \, ms$,a charge of $4 \, C$ is delivered to the ground. The power of the lightning strike is

The energy dissipated by a resistor is $10 \, mJ$ in $1 \, s$ when an electric current of $2 \, mA$ flows through it. The resistance is $....... \, \Omega$ (Round off to the Nearest Integer).

What is the maximum voltage that can be safely applied across a resistor of $196 \,\Omega - 1 \,W$ rating? .......... $volt$

$A$ railway compartment is lit up by thirteen lamps,each taking $2.1\,A$ at $15\,V$. The heat generated per second in each lamp will be ............ $cal$.

$A$ potential $V_0$ is applied across a uniform wire of resistance $R$. The power dissipation is $P_1$. The wire is then cut into two equal halves and a potential of $V_0$ is applied across the length of each half. The total power dissipation across two wires is $P_2$. The ratio $P_2: P_1$ is $\sqrt{x}: 1$. The value of $x$ is $.............$.

The emf of a battery is $2\, V$ and its internal resistance is $0.5 \,\Omega$. The maximum power which it can deliver to any external circuit will be ............. $watt$.