question_answer

A cylindrical conductor of radius R is carrying a 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:                  [NEET 5-5-2019]

A)

B)

C)

D)

Correct Answer: A

Solution :

            \[{{B}_{inside}}=\frac{{{\mu }_{0}}id}{2\pi {{R}^{2}}}\] \[{{B}_{in}}\propto d\] \[{{B}_{out}}=\frac{{{\mu }_{0}}i}{2\pi d}\] \[{{B}_{out}}\propto \frac{1}{d}\]