Question

Water is being boiled in a flat bottomed kettle placed on a stove The area of the bottom is `300cm^(2)` and the thickness is `2mm` If the amount pf steam produced is `1gm min^(-1)` then the difference of the temperature between the inner and the outer surface of the bottom is (thermal conductivity of the matrial of the kettle `0.5calcm^(-1)C^(-1)` latent heat of the steam is equal to `540calg^(-1))` .
A. `12^(@)C`
B. `1.2^(@)C`
C. `0.2^(@)C`
D. `0.012^(@)C`

Answer 1

Correct Answer - D
`(dtheta)/(dt) = L.(dm)/(dt)` = Heat transfer from bottom = `(TD)/(l//KA)`
Heat TD = desired temperature difference
`therefore` `(L.l.(dm)/(dt))/(KA) = ((540)(2 xx 10^(-1)(1/60)))/(0.5 xx 300)=0.012^(@)`C