One kg of water, at , is heated in an electric kettle whose heating element has a mean (temperature averaged) resistance of . The rms voltage in the mains is 200 V. Ignoring heat loss from the kettle, time taken for water to evaporate fully, is close to :
[ Specific heat of water =, Latent heat of water = 2260 kJ/kg]
16 minutes
22 minutes
3 minutes
10 minutes
Heat developed in a resistor -
When a steady current flows through a resistance R for time t , the loss in electric potential energy appears as increased thermal energy(Heat H) of resistor and
The power devoleped = (from Ohm's law)
- wherein
Unit of heat is joule (J)
Unit of power is watt (W)
Option 1)
16 minutes
Option 2)
22 minutes
Option 3)
3 minutes
Option 4)
10 minutes
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