The voltage of clouds is $4 \times 10^6\,volt$ with respect to round. In a lighteing strike lasting $100\,m\,sec$, a charge of $4\,coulombs$ is delivered to the ground. The power of lightening strike is

Three identical resistors $R_1=R_2=R_3$ are connected as shown to a battery of constant e.m.f. The power dissipated is ...........

A battery of internal resistance $4\, ohm$ is connected to the network of resistance as hown.  In the order that the maximum power can be delivered to the network, the value of $R$ in ohm should be :-

A constant voltage is applied between the two ends of a metallic wire. If both the length and the radius of the wire are doubled, the rate of heat developed in the wire

Resistances ${R_1}$ and ${R_2}$ are joined in parallel and a current is passed so that the amount of heat liberated is ${H_1}$ and ${H_2}$ respectively. The ratio $\frac{{{H_1}}}{{{H_2}}}$ has the value

The power rating of an electric motor which draws a current of $3.75\, amperes$ when operated at $200\, V$ is about