Advertisements
Advertisements
प्रश्न
An electric heater is rated 1500 W. How much energy does it use in 10 hours?
Advertisements
उत्तर
Here, the power of the electric heater, P = 1500 W
Time for which it is used, t = 10 h
Energy used by the electric heater, i.e.,
W = P × t
= 1500 W × 10 h
= 15000 W h
= 15 kW h
Energy consumed = `15 "kW h" × (3.6 xx 10^6 "J")/(1 "kW h")`
= 5.4 × 107J ...(∵ 1 kW h = 3.6 × 106 J)
APPEARS IN
संबंधित प्रश्न
Define 1 watt of power.
A battery lights a bulb. Describe the energy changes involved in the process.
What is the work done by the force of gravity on a satellite moving round the earth? Justify your answer.
A person holds a bundle of hay over his head for 30 minutes and gets tired. Has he done some work or not? Justify your answer.
Find the energy in joules consumed in 10 hours by four devices of power 500 W each.
Define kilowatt-hour.
What is the power of a body which is doing work at the rate of one joule per second?
A trolley is pushed along a road with a force of 400 N through a distance of 60 m in 1 minute. Calculate the power developed.
The power output of an engine is 3kW. How much work does the engine do in 20 s?
Which one of the following statements about power stations is not true?
