A $220\, volt$, $1000\, W$ bulb is connected across a $110\, volt$ mains supply. The power consumed will be ............ $W$
$1000$
$750$
$500$
$250$
A heater of $220\, V$ heats a volume of water in $5\,\min$ time. A heater of $110\, V$ heats the same volume of water in ............... $min$
Assertion : When current through a bulb decreases by $0.5\%$, the glow of bulb decreases by $1\%$.
Reason : Glow (Power) which is directly proportional to square of current.
Two identical batteries, each of $e.m.f.$ $2\, volt$ and internal resistance $1.0\, ohm$ are available to produce heat in an external resistance $R = 0.5\,ohm$ by passing a current through it. The maximum Joulean power that can be developed across $R$ using these batteries is ............. $watt$
An electric heater kept in vacuum is heated continuously by passing electric current. Its temperature
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)