An electric bulb marked $40\, W$ and $200\, V$,is used in a circuit of supply voltage $100\, V$. Now its power is (in $, W$)

An electric bulb is marked $100\ W, 230\ V$. If the supply voltage drops to $115\ V$,how much heat (in $J$) is produced by the bulb in $20\ min$?

Two bulbs have resistances in the ratio $1 : 2$. They are connected in parallel to a constant voltage source. What is the ratio of power dissipated in them?

$A$ $5\,^{\circ}\text{C}$ rise in temperature is observed in a conductor by passing a current. When the current is doubled the rise in temperature will be approximately ........... $^{\circ}\text{C}$

$5.0 \, A$ current is set up in an external circuit by a $6.0 \, V$ storage battery for $6.0 \, \text{minutes}$. The chemical energy of the battery is reduced by:

For driving a current of $2\, A$ for $6$ minutes in a circuit, $1000\, J$ of work is to be done. The $e.m.f.$ of the source in the circuit is ................ $V$.