Q 12-06-005NEETNEET 2025Top questionMedium
AB is a part of an electrical circuit (see figure). The potential difference $V_A - V_B$, at the instant when current $i = 2$ A and is increasing at a rate of $1$ amp / second is:
Answer: (D) $10$ volt
Go from A to B along the current and add up the potential drops.
Inductor: drop $= L\dfrac{di}{dt} = 1 \times 1 = 1$ V.
Battery: the current enters at the positive (longer) plate and leaves at the negative plate, so the potential drops by $5$ V.
Resistor: drop $= iR = 2 \times 2 = 4$ V.
$$V_A - V_B = 1 + 5 + 4 = 10\ \text{V}$$
Solution by Sreeraj P, M.Sc Physics