Question

The northk and south poles of a bar magnet are situated 0.4 cm inside from the geometric ends of the magnet. If the geometric length of the magnet is 6 cm, then its effective length is ________ mm.
A. 48
B. 52
C. 56
D. 54

Answer 1

Geometrical length of the magnet =6 cm.
Therefore, effective length of the magnet`=6-(2xx(0.4))`
`=5.2 cm `
`=52mm`.
Hence , the correct option is (b).