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)
$3600$
$2800$
$2450$
$2500$
A heater coil connected to a supply of a $220\, V$ is dissipating some power ${P_1}.$ The coil is cut into half and the two halves are connected in parallel. The heater now dissipates a power ${P_2}.$ The ratio of power ${P_1}\,\,:\,\,{P_2}$ is
Two cities are $150\,\, km$ apart. Electric power is sent from one city to another city through copper wires. The fall of potential per $km$ is $8\,\, volt$ and the average resistance per km is $0.5 \,\,\Omega .$ The power loss in the wire is
A uniform metallic wire of length $L$ is mounted in two configurations. In configuration $1$ (triangle), it is an equilateral triangle and a voltage $V$ is applied to corners $A$ and $B$. In configuration $2$ (circle), it is bent in the form of a circle and the potential $V$ is applied at diametrically opposite points $P$ and $Q$. The ratio of the power dissipated in configuration $1$ to configuration $2$ is
If a high power heater is connected to electric mains, then the bulbs in the house become dim, because there is a
Two bulbs one of $200$ $\mathrm{volts},$ $60$ $\mathrm{watts}$ and the other of $200$ $\mathrm{volts},$ $100$ $\mathrm{watts}$ are connected in series to a $200$ $\mathrm{volt}$ supply. The power consumed will be ................ $\mathrm{watt}$