The potential difference between the points A and C in the given circuit is:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 7.5 V
The circuit is a single loop: the 10 V cell and the three resistors are all in series, so the same current flows through each of them (the cell is taken as ideal).
\( R_{\mathrm{total}} = 4 + 2 + 2 = 8\,\Omega \)
\( \displaystyle I = \frac{10\,\mathrm{V}}{8\,\Omega} = 1.25\,\mathrm{A} \)
Between A and C, take the path through B, which has only resistors: the \( 4\,\Omega \) and the \( 2\,\Omega \) between B and C.
\( V_{AC} = I\,(4 + 2) = 1.25 \times 6 = 7.5\,\mathrm{V} \)
The other path gives the same value: the emf minus the drop across the \( 2\,\Omega \) next to the cell, \( 10 - 1.25 \times 2 = 7.5\,\mathrm{V} \).