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प्रश्न
What changes in energy occur in an electric heater?
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उत्तर
In an electric heater, electrical energy changes to heat energy.
संबंधित प्रश्न
An electric heater is rated at 2 kW. Electrical energy costs Rs 4 per kWh. What is the cost of using the heater for 3 hours?
(a) Rs 12
(b) Rs 24
(c) Rs 36
(d) Rs 48
Name the S.I. unit of electrical energy. How is it related to Wh?
What is the resistance, under normal working conditions of a 240 V electric lamp rated at 60 W? If two such lamps are connected in series across a 240 V mains supply, explain why each one appears less bright.
A simple electric circuit has a 30 V battery and a resistor ot 60 o. What will be the current in the circuit? The resistance of the oonnecting wires is negligible.
A coil of copper wire is connected to a galvanometer. What would happen if a bar magnet is:
(i) Pushed into the coil with its north pole entering first?
(ii) Held at rest inside the coil?
(iii) Pulled out again?
Water in an electric kettle connected to a 220 V supply took 5 minutes to reach its boiling point. How long will it take if the supply voltage falls to 200 V?
Name three main characteristics of an heating element.
Why is a concave reflector placed behind the heating element in a room heater.
Give two precautious that you would take while putting off an electric switch.
What is the commercial unit of electrical energy?
