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
Concept. Going from A to B along the current, add the potential drops across each element.
Step 1. Inductor. $L\dfrac{di}{dt} = 1 \times 1 = 1$ V.
Step 2. Battery. The current enters at the positive plate and leaves at the negative one: a drop of $5$ V.
Step 3. Resistor. $iR = 2 \times 2 = 4$ V.
Step 4. Total. $V_A - V_B = 1 + 5 + 4 = 10$ V.
Answer. $10$ volt (Option D).
Solution by Sreeraj P, M.Sc Physics