Question

Two similar accumulators each of emf $E$ and internal resistance $r$ are connected as shown in the following figure. Then the potential difference between $X$ and $Y$ is:

• A. 2E
• B. E
• C. zero
• D. none of these

Answer 1

Answer: (C)

If $I$ be the current in the circuit, then
$E+E =I r +I r=2 I r$
or $I =\frac{E}{r}$
$\therefore V_{x}-V_{y} =E-I r$
$=E-\frac{E}{r} \times r=0$