Question

An electric iron of heating element of resistance 88ohm is used at 220 volt for 2hours.The electric energy spent, in unit,will be:

Answer 1

Answer:

Geyser is rated for 2.2 kW or 2200 W.

current is 2200/220=10 A Resistance of heater coil=220/10=22 ohm

The resistance varies as the coil gets heated up

Resistance of 100 W bulb = R100 =220 x 220/100= 484 ohm

Resistance of 10 W bulb = R10 =220 x 220/10= 4840 ohm

3. So resistance of 10 W bulb is more.

Explanation: