The potential difference \( (V_A - V_B) \) between points A and B in the given figure is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → +17 V
Follow the path from A to B in the direction of the 1 A current and add the potential changes. Across a resistor, the potential falls by \( IR \) in the direction of the current. Across a cell, the potential falls by its emf when the path goes from the positive to the negative terminal. In the figure the current enters the 10 V cell at its positive (longer) plate, so the potential falls across it as well.
\( V_A - (1\times5) - 10 - (1\times2) = V_B \)
\( V_A - V_B = 5 + 10 + 2 = 17\,\mathrm{V} \)