Two resistors of resistance, $100\,\Omega$ and $200\,\Omega$ are connected in parallel in an electrical circuit. The ratio of the thermal energy developed in $100\,\Omega$ to that in $200\,\Omega$ in a given time is:
$2: 1$
$1: 4$
$4: 1$
$1: 2$
Assertion : Long distance power transmission is done at high voltage.
Reason : At high voltage supply power losses are less.
Which device is used to transmit voltage over large distance ? why ?
The heat produced by a $100\, watt$ heater in $2$ minute will be equal to
Four identical electrical lamps are labelled $1.5\,V$, $0.5\,A$ which describes the condition necessary for them to operate at normal brightness. A $12\,V$ battery of negligible internal resistance is connected to lamps as shown, then
A $60\, watt$ bulb operates on $220\,V$ supply. The current flowing through the bulb is