Hot water cools from 60,^oC to 50,^oC in first 10, min and to 42,^oC in next 10, min . temperature o

English

Gujarati

Hindi

10-2.Transmission of Heat

normal

Hot water cools from $60\,^oC$ to $50\,^oC$ in the first $10\, min$ and to $42\,^oC$ in the next $10\, min$. The temperature of the surrounding is ........ $^oC$

A

$50$

B

$10$

C

$15$

D

$20$

Solution

$\frac{\mathrm{T}_{1}-\mathrm{T}_{2}}{\mathrm{t}}=\mathrm{k}\left(\frac{\mathrm{T}_{1}+\mathrm{T}_{2}}{2}-\mathrm{T}_{0}\right)$

$\frac{60-50}{10}=\mathrm{k}\left(\frac{60+50}{2}-\mathrm{T}_{0}\right)$

$\frac{50-42}{10}=\mathrm{k}\left(\frac{50+42}{2}-\mathrm{T}_{0}\right)$

By solving $\mathrm{T}_{0}=10^{\circ} \mathrm{C}$

Standard 11

Physics

Share

Similar Questions

Which of the following cylindrical rods will coduct most heat when their ends are maintained at the same steady temperatures?

normal

A rod of length $2m$ at $0^o C$ and having expansion coefficient $ \alpha = (3x + 2) \times 10^{-6}$ $ ^o C^{-1}$ where $x$ is the distance (in $cm$) from one end of rod. The length of rod at $20^o C$ is ……… $m$

normal

If the temperature of a black body increases from $7\,^oC$ to $287\,^oC$ then the rate of energy radiation increases by

normal

A sphere and a cube of same material and same volume are heated upto same temperature and allowed to cool in the same surroundings. The ratio of the amounts of radiations emitted will be

normal

A body cools from $62\,^oC$ to $50\,^oC$ in $10\, minutes$ and to $42\,^oC$ in next $10\, minutes$. The temperature of the surrounding is ……….. $^oC$

normal