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)

$2$ V

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