As per the given figure, if $\frac{\mathrm{dI}}{\mathrm{dt}}=-1 \mathrm{~A} / \mathrm{s}$ then the value of $\mathrm{V}_{\mathrm{AB}}$ at this instant will be $\_\_\_\_$ V.

JEE Main · 2023 · 30 Jan 2023 · Shift 1 · Electromagnetic Induction

As per the given figure, if

\frac{dI}{dt} = - 1 A / s

then the value of

V_{AB}

at this instant will be

____

Answer: 30

Solution

Moving from A to B along the branch, the

2 A

current in the

12 Ω

resistor produces a drop

I R = 24 V

, the inductor contributes

- L \frac{d I}{d t} = - 6 \times (- 1) = + 6 V

because the falling current makes it act like a source, and the

12 V

cell drops a further

12 V

. Collecting these,

V_{A} - 24 + 6 - 12 = V_{B}

, so

V_{A B} = V_{A} - V_{B} = 30 V

JEE Main · 2023 · 30 Jan 2023 · Shift 1 · Integer answer

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