In India electricity is supplied for domestic use at $220 \,V$. It is supplied at $110 \,V$ in USA. If the resistance of a $60 \,W$ bulb for use in India is $R$, the resistance of a $60 \,W$ bulb for use in USA will be
$R$
$2 R$
$\frac{R}{4}$
$\frac{R}{2}$
Two electric bulbs whose resistance are in the ratio of $1: 2$, are connected in parallel to a constant voltage source. The power dissipated in them has the ratio
For reduce in Ohmic loss transmission of electric power at very far distance of electric power is done at very high voltage ?
The circuit below is used to heat water kept in a bucket. Assuming heat loss only by Newton's law of cooling, the variation in the temperature of the water in the bucket as a function of time is depicted by
A railway compartment is lit up by thirteen lamps each taking $2.1\, amp$ at $15\, volts$. The heat generated per second in each lamp will be ............ $cal$
A bulb of $100\, W$ is connected in parallel with an ideal inductance of $1\, H$. This arrangement is connected to a $90\,V$ battery through a switch. On pressing the switch, the