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The current in a purely inductive circuit is 5 sin(49π t-30°) A. If the inductance is 30 mH, the voltage across the inductor is [Letπ=(22)/7]

Asked in JEE Main 28th July 1st Shift 2022 · Behaviour of R, L and C separately

• (1) 1.47 sin(49π t-30°)
• (2) 1.47 sin(49π t+60°)
• (3) 23.1 sin(49π t-30°)
• (4) 23.1 sin(49π t+60°)

Step-by-step solution

Why the other options are wrong

• (1) Wrong amplitude and no 90° lead of voltage over current.
• (2) Correct +90° shift but a mis-scaled reactance.
• (3) Right amplitude but forgets the inductor voltage leads current by 90°.

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