CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

A current is flowing through a thin cylindrical shell of radius R. If energy density in the medium, due to magnetic field, at a distance r from the axis of the shell is equal to U, then which of the following graphs is correct?


Your Answer
A
Correct Answer
B
Your Answer
C
Your Answer
D

Solution

The correct option is B

Using Ampere's Circuital law over the cross section of the thin shell,
B.dl=μ0ienclosed

Case 1: For r<R


ienclosed=0
B.dl=0
Binside=0

Case 2: For r=R
B.dl=μ0ienclosed
B×2πR=μ0I
Bsurface=μ0I2πR

Case 2: For r>R


B.dl=μ0ienclosed
B×2πr=μ0I
Bsurface=μ0I2πr

Hence, the variation of B w.r.t r is represented by the following graph.



Energy density due to a magnetic field B is given by
U=B22μ0 where μ0 is the magnetic permeability of free space.  
 
i.e UB2
So, the graph representing variation of U with r is (b).

 

flag
 Suggest corrections
thumbs-up
 
0 Upvotes


Similar questions
View More


People also searched for
View More



footer-image