A vibrations magnetometer consists of two indentical bar magnet placed one over the other that they are perpendicular and bisect each other. The time period of oscillation in a horizontal magnetic field is `2^(5//4)` s. One of the magnets is removed and if the other magnet oscillates in the same field, then the time period in second is :

Options

A. `2^(1//4)`
B. `2^(1//2)`
C. `2`
D. `2^(5//4)`

Answer

C

Explanation

`M_(R)=sqrt(M^(2)+M^(2))=Msqrt(2)`
`T=2pisqrt((2I)/(Msqrt(2)H))`
When one of magnet is removed.
Then `T^(')=2pisqrt(I/(MH))`
`:. T^(')/T=1/2^(1/4)`