Two opposite faces of a cubical piece of iron (thermal conductivity = 0.2, CGS units) are at {100^o}

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10-2.Transmission of Heat

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The two opposite faces of a cubical piece of iron (thermal conductivity $= 0.2\, CGS$ units) are at ${100^o}C$ and ${0^o}C$ in ice. If the area of a surface is $4c{m^2}$, then the mass of ice melted in $10$ minutes will be ...... $gm$

A

$30 $

B

$300 $

C

$5$

D

$50$

Solution

(b) $Q = mL = KA\frac{{({\theta _1} – {\theta _2})}}{l}t$ $ \Rightarrow \;m = \frac{1}{L} \times KA\frac{{({\theta _1} – {\theta _2})}}{l} \times t$

$ = \frac{1}{{80}} \times 0.2 \times 4 \times \frac{{(100 – 0)}}{{\sqrt 4 }} \times 10 \times 60$

$ = \frac{{0.2 \times 4 \times 100 \times 600}}{{80 \times 2}} = 300\;gm$

Standard 11

Physics

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