Question

Two magnetic poles each of magnetic pole strength $16Am$ are placed at a distance of $2m$ apart. Find magnetic force acting on each pole.

• A. $4\times {10}^{-7}N$
• B. $16\times {10}^{-7}N$
• C. $32\times {10}^{-7}N$
• D. $64\times {10}^{-7}N$

Answer 1

The correct option is D $64\times {10}^{-7}N$

Force acting on each pole is $F$

$F=\frac{{\mu }_0}{4\pi }\frac{m_1{m}_2}{d^2}$

where $m_1$ and $m_2$ are magnetic moment of magnets.

$d=$ distance between the magnet.

$F=\frac{4\pi \times {10}^{-7}}{4\pi }\frac{16\times 16}{2^2}=64\times {10}^{-7}N$