ϕouter=(μ0nKte−αt)4πR2
ϵ=dt−dϕ=−μ0nK4πR2(e−αt[1−αt])
iinduced=Resistance−ce−αt[1−αt]
At t=0, Iinduced=−ve
From the above equation and initial value of current we can say the correct graph is B.
JEE Main 2019 — Physics Electromagnetism
2019mcqhard
A very long solenoid of radius R is carrying current I(t)=kte−αt(k>0), as a function of time (t≥0). Counterclockwise current is taken to be positive. A circular conducting coil of radius 2R is placed in the equitorial plane of the solenoid and concentric with the solenoid. The current induced in the outer coil is correctly depicted, as a function of time, by:
Official previous-year question
Held on 9 Apr 2019 · Verified 6 Jul 2026.
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