In India,electricity is supplied for domestic use at $220\,V$. It is supplied at $110\,V$ in the $USA$. If the resistance of a $60\,W$ bulb for use in India is $R$,then the resistance of a $60\,W$ bulb for use in the $USA$ will be:

How much heat (in $cal$) is produced when a $210 \, W$ bulb is kept on for $5 \, min$? (Given $J = 4.2 \, J/cal$)

Define kilowatt hour and power.

Two electric bulbs have ratings $P_1 \text{ watt}, V \text{ volt}$ and $P_2 \text{ watt}, V \text{ volt}$. If they are connected in parallel to a $V \text{ volt}$ supply,the total power consumed will be:

Four wires of the same diameter are connected in turn between two points,maintained at a constant potential difference. Their resistivities and lengths are: $\rho$ and $L$ (wire $1$),$1.2\rho$ and $1.2L$ (wire $2$),$0.9\rho$ and $0.9L$ (wire $3$),and $\rho$ and $1.5L$ (wire $4$). Rank the wires according to the rates at which energy is dissipated as heat,greatest first.

$A$ bulb of $100 \text{ W}$ rating is connected with $220 \text{ V}$ supply. The resistance of the bulb is . . . . . . .