Question

A current i amp flows along an infinitely long straight thin conductor. Then the magnetic induction at any point on the axis of the conductor is

• A. Infinity
• B. zero
• C. $\frac{{\mu }_{0}2i}{4\pi r}$
• D. $\frac{{\mu }_0}{4\pi }\frac{i}{r}$

Answer 1

The correct option is B zero

$Sin\theta =0$ on any pt. on the axis of conductor carrying current
$B=\frac{{\mu }_o}{4\Pi }i\frac{dlSin\theta }{r^2}$