It takes 10 minutes to cool a liquid from 61^oC to 59^oC . If room temperature is 30^oC then time ta

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10-2.Transmission of Heat

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It takes $10$ minutes to cool a liquid from $61^oC$ to $59^oC$. If room temperature is $30^oC$ then time taken in cooling from $51^oC$ to $49^oC$ is ....... $\min$

A

$10$

B

$11$

C

$13$

D

$15$

Solution

(d) In first case $\frac{{61 – 59}}{{10}} = K\left[ {\frac{{61 + 59}}{2} – 30} \right]$….$(i)$ n

second case $\frac{{51 – 49}}{{10}} = K\left[ {\frac{{51 + 49}}{2} – 30} \right]$….$(ii)$

By solving $t = 15$ $min.$

Standard 11

Physics

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