An electric heater supplies heat to a system at a rate of 100 W. If system performs work at a rate of 75 joules per second. At what rate is the internal energy increasing ?

An electric heater is rated 1500 W. How much energy does it use in 10 hour?

The radius of a circular plate increase at the rate of 0.1 cm per second. At what rate does the area increase when the radius of plate is 5/pi cm ?

A system absorbs 2 Kcals heat and does 500 J of work, then internal energy of the system will be …….

An electric heater of resistance 8 ohm draws 15A from the service mains for 2 hours. Calculate the rate at which heat is developed in the heater.

An electric bulb is rated 220V and 100W. When it is operated on 110V the power consumed will be …………… .

An electric iron consumes energy at a rate of 840 W, when heating is at the maximum rate and 360 W, when heating is atthe minimum. The voltage is 220V. What are the current and the resistance in each case?