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Question
At a given time, a house is supplied with 100 A at 220 V. How many 75 W, 220 V light bulb could be switched on in the house at the same time (if they are all connected in parallel)?
Options
93
193
293
393
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Solution
293
Explanation:
Total power provided in the house,
P = VI = `100 "A" xx 220 "V"` = 22000 W
This is the maximum power that can be drawn in the house.
Total power drawn by x bulbs = 75x W
∴ Maximum power x bulbs can draw = 22000 W
⇒ 75x = 22000`
⇒ x = `22000/75~~293`
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