Question

A resistor $R_{1}$ dissipates the 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 $R_{2}$

Answer 1

Answer: (A)

Decreases

Answer 2

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 $(R_{1} + R_{2})$ is higher than that in the first case (R₁). Therefore power dissipation in the second case will be decreased.