With a standard rectangular bar magnet, the time period in the uniform magnetic field is `4 sec`. The bar magnet is cut parallel to its length into `4` equal pieces. The time period in the uniform magnetic field when the piece is used (in sec) (bar magnet breadth is small)

Options

A. 16
B. 8
C. 4
D. 2

Answer

C

Explanation

Time period of magnet, `T-2pisqrt((l)/(MB))`
When magnet is cut parallel to its length into four equal pieces.