Q. Resistances $R_{1}$ and $R_{2}$ are joined in parallel and a current is passed so that the amount of heat liberated is $H_{1}$ and $H_{2}$ respectively. The ratio $\frac{H_{1}}{H_{2}}$ has the value
A) $\frac{R_{2}}{R_{1}}$
B) $\frac{R_{1}}{R_{2}}$
C) $\frac{R_{1}^{2}}{R_{2}^{2}}$
D) $\frac{R_{2}^{2}}{R_{1}^{2}}$
Explanation
(a) Heat produced$\ H = \frac{V^{2}t}{4.2R} = H \propto \frac{1}{R}\ $Hence$\ \frac{H_{1}}{H_{2}} = \frac{R_{2}}{R_{1}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.