Grade upto college level Magnetism

PLzz solve this ques.
Interesting ques..
Interesting ques..
A circular conductin loop of radius r₀ &having resistance per unit length is placed vertically in magnetic field B which is constant in space &time.The ends of the loop are crossed and pulled in opposite directions with velo v such dat the loop always remain circular and the radius of the loop goes on decreasing..then
1)radius of loop changes with time t as???
2)Find the current induced in the loop..

Deepak Patra

12 Years agoGrade upto college level

1 Answer

ROSHAN MUJEEB

6 Years ago

Perimeter is decreasing at a rate of 2v
ddt(2πr)=2v⇒drdt=vπddt(2πr)=2v⇒drdt=vπ
∴r=(r0−vπt)∴r=(r0-vπt)
ϕ=Bπr2⇒ɛ=∣∣∣−dϕdt∣∣∣=B2πrdrdtϕ=Bπr2⇒ɛ=|-dϕdt|=B2πrdrdt
∴ɛ=2Bπ(r0−vπt)vπ=2Bv(r0−vπt)∴ɛ=2Bπ(r0-vπt)vπ=2Bv(r0-vπt)
I=ϕR=2Bvrλ.2πr=Bvπλ