1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# 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 equatorial 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-

A
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

## The correct option is C Flux linked with the coil is, ϕ=BA=(μ0nI)A=μ0n(kte−αt)A ∵ e=−dϕdt=−μ0nAkddt(te−αt) =−μ0nAk[te−αt(−α)+e−αt×1] =−μ0nAk[e−αt(1−αt)] iind=eResistance=−μ0nAkResistance[e−αt(1−αt)] At t=0, i⇒−ve <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, (A) is the correct answer.

Suggest Corrections
21
Join BYJU'S Learning Program
Related Videos
Motional EMF
PHYSICS
Watch in App
Join BYJU'S Learning Program