Question

The pole strength of a horse shoe magnet is 90 Am and distance between the poles is 6 cm. The magnetic induction at mid point of the line joining the poles is,

• A. ${10}^{-2}T$
• B. Zero
• C. $2\times {10}^{-2}T$
• D. ${10}^{-4}T$

Answer 1

Answer: (C)

$2\times {10}^{-2}T$

$m=90Am$
$l=6$
$B=\frac{{\mu }_{0}m}{4\pi d^2}$
$={10}^{-2}T$
Net magnetic field at the center$=2B$
$=2\times {10}^{-2}T$