On 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 `200 V`. Ignoring heat loss from the kettle, time taken for water to evaporate fully is close to :
[Specific heat of water `= 4200 J//kg .^(C)`, Letent heat of water `= 2260 kJ//kg`]

Options

A. 3 minuntes
B. 16 minutes
C. 22 minutes
D. 10 minutes

Answer

C

Explanation

`(ms Delta theta)+mL=l_(rms)^(2)Rt`
`impliest=((ms Delta theta +mL)/(l_(rms)^(2)R))`
`t~~22` minutes.