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Question
A bulb marked 12 V, 24 W operates on a 12 volt car battery for 20 minutes. Calculate:
(i) The current flowing through it, and
(ii) The energy liberated.
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Solution
Given, Voltage = 12 V, power = 24 W, time = 20 mins. = 1200 s.
(i) Currrent, I = `"P"/"V" = 24/12` = 2 A
(ii) energy liberated, H = VIt = 12 x 2 x 1200 = 28,800 J
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