Question

A brass boiler has a base area of `0.15m^2` and thickness 1.0 cm it boils water at the rate of `6.0 kg//min`, When placed on a gas. Estimate the temperature of the part of the flame in contact with the boiler. Thermal conductivity of brass`=109 J//s-.^@C` ) and heat of vapourization of water `=2256 J//g`.
A. `2400 K`
B. `240 "^(@)C`
C. `2400 "^(@)C`
D. `24000 "^(@)C`

Answer 1

Rate of supply of heat to water `=` rate at which heat is conducted by boiler
`L(dm)/(dt)=(dQ)/(dt)=(KA(theta-100))/(t)`
`(6xx2256xx10^(3))/(60)=(107.4xx0.15xx(theta-100))/(10^(-2))`
Solving, `theta=240^(@)C`