JEE Main · 2026 · 06 Apr 2026 · Shift 1 · Electromagnetic Induction

An inductor of inductance 10 mH having resistance of

100Ω

is connected to battery of E.M.F. 1.0 V through a switch as shown in the figure below. After switch is closed, the ratio of instantaneous voltages across the inductor when the current passing through it is 2 mA and 4 mA is

____

(A) $4/3$ ✓ Correct
(B) $3/4$
(C) $5/3$
(D) $3/5$

Answer: (A)

Solution

Around the loop

E = i R + V_{L}

, so the inductor voltage is

V_{L} = E - i R = 1 - 100 i

. At

i = 2

mA,

V_{L} = 1 - 100 \times 2 \times 1 0^{- 3} = 0.8

V; at

i = 4

mA,

V_{L} = 1 - 0.4 = 0.6

V. Their ratio is

\frac{0.8}{0.6} = \frac{4}{3}

JEE Main · 2026 · 06 Apr 2026 · Shift 1 · Single correct option

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