Question

Water is being boiled in a flat bottom kettle placed on a stove. The area of the bottom is
$3000{cm}^2$ and its thickness is $2mm$. If the amount of steam produced is $1g/min$, calculate the difference of temperatures between the inner and outer surface of the bottom. Thermal conductivity for the material of the kettle is $0.5cal{K}^{-1}{s}^{-1}c{m}^{-1}$, and the latent heat of stream is $540cal/g$.

• A. $1.2\times {10}^{-3}{}^{o}C$
• B. $2.4\times {10}^{-3}{}^{o}C$
• C. $3.6\times {10}^{-3}{}^{o}C$
• D. $4.8\times {10}^{-3}{}^{o}C$

Answer 1

The correct option is A $1.2\times {10}^{-3}{}^{o}C$

$Q=KA\left(\frac{\Delta \theta }{{\Delta }_X}\right)t$

$540=0.5\times 3000\left(\frac{\Delta \theta }{0.2}\right)60$

$\Delta \theta =\frac{108}{90000}=(12\times {10}^{-4}{)}^{o}C$