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Thursday, 14 May 2026
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It takes 4 minutes to boil a quantity of water electrically. How long will it take to ...

It takes 4 minutes to boil a quantity of water electrically. How long will it take to boil same quantity of water using the same heating coil but with the current doubled? (neglecting any external heat loss).
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  • A 64 minutes
  • B 32 minutes
  • C 8 minutes
  • D 2 minutes
  • E 1 minute
Correct Answer: Option E
Explanation:
D ∝ l2
E will increase 4 times when current is doubled.
Therefore time will decrease by a factor of 4, which is 1 minute.

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