Calculate the time in which 4.8 kJ of energy would be expended when an electric heater of resistance 1.8 x 103Ω is used on a 240 V mains supply. (Neglect heat losses to the surrounding).
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Correct Answer: Option A
Explanation:
E = V2t/Rt =
ER/V2
=
4800 x 1.8 x 103/240 x 240
= 150s
E = V2t/Rt =
ER/V2
=
4800 x 1.8 x 103/240 x 240
= 150s