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An electric kettle with negligible heat capacity is rated at 2000W. If 2.0kg of water ...

An electric kettle with negligible heat capacity is rated at 2000W. If 2.0kg of water is put in it, how long will it take the temperature of water to rise from 20OC to 100OC? [specific heat capacity of water = 4200Jkg-1k-1]
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
  • A 420S
  • B 336S
  • C 168S
  • D 48S
Correct Answer: Option B
Explanation:
Heat energy = Elect. energy
mc\(\theta\) = power x time
2 x 4200 x (100 - 20) = 2000 x t
t = 336s

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