A cylinderical conductor of radius R is carrying constant current. The plot of the magnitude of the magnetic field, B with the distance, d from the centre of the conductor , is correctly represented by the figure:

Options

A.
B.
C.
D.

Answer

D

Explanation

From ampere circuital law
`ointB.dl-=mu_(0)I'rArr=(1)/(piR^(2))xxpir^(2)`
`B2pir=mu_(0)(I)/(piR^(2))xxpir^(2)`
`B=(mu_(0)I)/(2piR^(2))r`
`B_("inside") alpha r`
`B_("outside")`
`ointB.dl=mu_(0)I`
`B2pir=mu_(0)I`
`B=(mu_(0)I)/(2pir)`
`B alpha(1)/(r)`