Advertisements
Advertisements
Question
When an electric lamp is connected to 12 V battery, it draws a current of 0.5 A. The power of the lamp is:
(a) 0.5 W
(b) 6 W
(c) 12 W
(d) 24 W
Solution
6 W
Power, P = VI = 12 V x 0.5 A = 6 W
APPEARS IN
RELATED QUESTIONS
An electric motor takes 5 A from a 220 V line. Determine the power of the motor and the energy consumed in 2 h.
An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be ______.
If a bulb of 60W is connected across a source of 220V, find the current drawn by it.
An electric bulb is connected to a 220 V power supply line. If the bulb draws a current of 0.5 A, calculate the power of the bulb.
Calculate the cost of operating a heater of 500 W for 20 hours at the rate of Rs 3.90 per unit.
An electrical appliance having a resistance of 200Ω is operated at 200 V. Calculate the energy consumed by the appliance in 5 minutes (i) in joules (ii) in kWh.
State the S.I. units of electrical power and electrical energy.
(i) Define the household unit of electricity.
(ii) What is the voltage of the electricity that is generally supplied to a house?
An electric bulb is marked 100 W, 230 V. What does this mean?
I ampere of current is passed through a resistor of resistance R ohm for time t second. Obtain expression for
(i) the electrical energy, and
(ii) the electrical power spent.
A bulb is connected to a battery of e.m.f. 6V and internal resistance 2Ω A steady current of 0.5A flows through the bulb. Calculate the heat energy dissipated in the bulb in 10 minutes.
