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1 kg of water, at 20 °C is heated in an electric kettle whose heating element has a mean (temperature averaged) resistance of 20 Ω . The rms voltage…

JEE Main 2019 — Physics Thermodynamics

2019mcqhard

1kg1\mathrm{kg}1kg of water, at 20∘C20 ^{\circ}C20∘C is heated in an electric kettle whose heating element has a mean (temperature averaged) resistance of 20Ω.20 \Omega .20Ω. The rms voltage in the mains is 200V200 V200V. Ignoring heat loss from the kettle, time taken for water to evaporate fully is close to

[ Specific heat of water =4200 J{\mathrm{kg}}^{-1}^{\circ}{C}^{-1} Latent heat of water =2260kJkg−1=2260 kJk{g}^{-1}=2260kJkg−1 ]

Official previous-year question

Held on 12 Apr 2019 · Verified 6 Jul 2026.

Options

  1. A

    3min3\mathrm{min}3min

  2. B

    16min16\mathrm{min}16min

  3. C

    22min22\mathrm{min}22min

  4. D

    10min10\mathrm{min}10min

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