A cylinder wire of radius R is carrying uniformly distributed current I over its cross-section. If a circular loop of radius r is taken as amperian loop, then the variation value of `oint vec(B)* Vec(dl)` over this loop with radius 'r' of loop will be best represented by

Options

A.
B.
C.
D.

Answer

B

Explanation

`ointvecB.vecdl=mu_(0)(i)/(piR^(2))xxpir^(2)`
`=(mu_(0)ir^(2))/R^(2) ointvecB.vecdl=mu_(0)i`