Question

A straight current-carrying wire passes through a uniform magnetic field as shown in the figure above. Find out the point at which the magnetic field is the strongest?

• A. $A$
• B. $B$
• C. $C$
• D. $D$
• E. The magnetic field strength is uniform throughout

Answer 1

The correct option is C $C$

The magnetic field $B$ due to a current $I$ carrying wire of infinite length , at a distance $r$ is given by

$B=\frac{{\mu }_0}{4\pi }.\frac{2I}{r}$

it is clear that $B\propto 1/r$

if point $C$ is nearest (smallest $r$) to wire , then magnetic field $B$ will be maximum at $C$.