Question

The temperature gradient in a rod of $0.5m$ long is ${80}^{o}C/m$. If the temperature of hotter end of the rod is ${30}^{o}C$, then the temperature of the cooler end is

• A. $0^{o}C$
• B. ${-10}^{o}C$
• C. ${10}^{o}C$
• D. ${40}^{o}C$

Answer 1

The correct option is B ${-10}^{o}C$

Temperature gradient $=\frac{{\theta }_1-{\theta }_2}{l}$
Here, ${\theta }_1={30}^{o}C;l=0.5m$
$\therefore 80=\frac{30-{\theta }_2}{0.5}$
${\theta }_2=30-80\times 0.5$
$\Rightarrow {\theta }_2=30-40=-{10}^{o}C$