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One kg of water, at 20^(@)C, is heated i...

One kg of water, at `20^(@)C`, is heated in an electric kettle whose heating element has a mean (temperature averaged) resistance of `20 Omega`. The rms voltage in the mains is 200V. Ignoring heat loss from the kettle, time taken for water to evaporate fully, is close to: [specific heat of water= 4200J/kg `""^(@)C`], Latent heat of water = 2260kJ/kgI

A

16 minutes

B

10 minutes

C

22 minutes

D

3 minutes

Text Solution

Verified by Experts

The correct Answer is:
C
`mS DeltaT +mL =(V^2)/(R)t`
`1 xx 4200 xx 80 +1 xx 2.26 xx 10^6=((200)^2)/(20)t`
t=21.6 m=22 minutes.
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