List of top Physics Questions on Electric Power

An electric coil is rated $400\text{ W}$, $200\text{ V}$. It is cut into two equal parts and connected in parallel to the same source of $200\text{ V}$. Calculate the percentage increase in energy produced per second.
If three tube lights with power 10 W, 25 W and 50 W are connected in parallel to a source voltage V, then the effective power of the combination is
When an electric potential of 200 V is maintained between the ends of a conductor, a current of 3 A flows through it. The amount of heat energy dissipated in the time interval 25 s is
A constant current of 3A flows through a conductor having potential difference of 200V. Find heat developed in conductor in 25s.
The resistor \( R_1 = 30 \, \Omega \) and \( R_2 = 10 \, \Omega \) are connected in parallel to a 20 V battery. Find the heat developed in the resistor \( R_1 \) in one minute
The energy dissipated per unit time by a wire of resistance \(2R\) connected to a battery of voltage \(2V\) is
Across the \( 220 \, V \) source of internal resistance \( 20\Omega \), how many lamps of \( 40 \, W, 100 \, V \) can be connected in parallel so that all the lamps may glow with full brightness.
A bulb rated 60 W operates for 2 hours. How much energy does it consume in this time?
If an electric bulb of resistance \(400 \Omega\) is connected to an ac source of peak voltage 282.8 V, then the electric power of the bulb is
The ratio of powers of two motors is \(\frac{3\sqrt x}{\sqrt x+1}\), that are capable of raising 300 kg water in 5 minutes and 50 kg water in 2 minutes respectively from a well of 100 m deep. The value of x will be
A coil is placed in a time varying magnetic field. If the number of turns in the coil were to be halved and the radius of wire doubled, the electrical power dissipated due to the current induced in the coil would be: (Assume the coil to be short circuited.)
In a common emitter amplifier, the input resistance and output resistance are \(200\ \Omega\) and \(50\ \text{k}\Omega\) respectively. If the voltage gain of the amplifier is \(50\), then the power gain is
The resistance of the tungsten wire in the light bulb, which is rated at $120$ V/$75$ W and powered by a $120$ V direct-current supply, is
Two bulbs of equal power are connected in parallel and they totally consume 110 W at 220 V. The resistance of each bulb is
The power dissipated in the transmission cables carrying current I and voltage V is inversely proportional to
The power dissipated in the transmission cables carrying current I and voltage V is inversely proportional to
The power dissipated in the transmission cables carrying current I and voltage V is inversely proportional to

The power dissipated in the circuit shown in the figure is 30W. The value of R is

For a device, power consumed = 110 W and voltage supplied is 220 V. The number of electrons that flow in 1 is \(\frac{x}{4}\) × 1017 . Find x.