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 2019]

A)  

B)       

C)  

D)       

Correct Answer: A

Solution :

[a]

\[{{B}_{inside}}=\frac{{{\mu }_{0}}id}{2\pi {{R}^{2}}}\]

\[{{B}_{in}}\propto d\]

\[{{B}_{out}}=\frac{{{\mu }_{0}}i}{2\pi d}\]

\[{{B}_{out}}\propto \frac{1}{d}\]