Question

Three identical resistors each of resistance $R$ are connected to an ideal cell of voltage $V$ as shown. Total power dissipated in all three resistors is:

• A. $\frac{3V^2}{2R}$
• B. $\frac{3V^2}{R}$
• C. $\frac{V^2}{3R}$
• D. $\frac{2V^2}{3R}$

Answer 1

The correct option is D $\frac{2V^2}{3R}$

From the circuit diagram,
equivalent resistance of circuit,
$\left(R_{eq}\right)=R+\frac{R\times R}{R+R}=R+\frac{R^2}{2R}=R+\frac{R}{2}$
$R_{eq}=\frac{3R}{2}$
We know that,
power $\left(P\right)=\frac{V^2}{R}=\frac{V^2}{\frac{3R}{2}}$
$P=\frac{2V^2}{3R}$.