Q. A resistor $R_{1}$ dissipates power $P$ when connected to a certain generator. If the resistor $R_{2}$ is put in series with $R_{1},$ the power dissipated by $R_{1}$
A) Decreases
B) Increases
C) Remains the same
D) Any of the above depending upon the relative values of $R_{1}$ and $R_{2}$
Explanation
(a) Equivalent resistance in the second case $= R_{1} + R_{2} = R$
Now, we know that $P \propto \frac{1}{R}$
Since in the second case the resistance $\left( R_{1} + R_{2} \right)$ is higher than that in the first case $\left( R_{1} \right)$
Therefore power dissipation in the second case will be decreased
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.