A bar magnet of moment of inertia `49xx10^(-2)kg-m^(2)` vibrates in a magnetic field of induction `0.5xx10^(-4)` T. The time period of vibration is 8.8s. The magnetic moment of the bar magnet is

Options

A. `350 A-m^(2)`
B. `490 A-m^(2)`
C. `3300 A-m^(2)`
D. `5000 A-m^(2)`

Answer

D

Explanation

Time period of vibration magnetometer is,
`T=2pisqrt((I)/(MB_(H)))`
`implies8.82pisqrt((49xx10^(-2))/(Mxx0.5xx10^(-4))`
`M=((2pi)^(2)xx49xx10^(-2))/((8.8)^(2)xx0.5xx10^(_4))`
`therefore M=5000 A-m^(2).`