Question

If L be the length of a bar magnet then separation between the two poles is nearly

• A. $\frac{9}{10}L$
• B. $\frac{6}{7}L$
• C. $\frac{1}{3}L$
• D. $\frac{1}{2}L$

Answer 1

Answer: (B)

$\frac{6}{7}L$

Given: Length of a bar magnet = L

Solution: Original length of magnet refers to the geometrical length of the bar magnet, whereas the separation between the two poles is called magnetic length.

Since, Magnetic length is approximately equal to 0.83-0.85 times of the geometric length which is,

Magnetic Length= $\frac{6}{7}L$

where, L is the geometric length.

Hence, option (B) is correct.