Question

In the circuit , the potential difference between $A$ and $B$ is :

• A. 6 V
• B. 1 V
• C. 3 V
• D. 2 V

Answer 1

Answer: (D)

Potential difference across $AB$ will be equal to battery equivalent across $CD$
$V_{AB}=V_{CD}=\frac{\frac{E_1}{r_1}+\frac{E_2}{r_2}+\frac{E_3}{r_3}}{\frac{1}{r_1}+\frac{1}{r_2}+\frac{1}{r_3}}=\frac{\frac{1}{1}+\frac{2}{1}+\frac{3}{1}}{\frac{1}{1}+\frac{1}{1}+\frac{1}{1}}$
$=\frac{6}{3}=2V$