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^(3//4)`

Answer

C

Explanation

Initially `M_(1)= sqrt2M , I_(1)= 2I`
Finally `M_(2)= M, I_(2)= I`
`(T_(1))/(T_(2)) = sqrt((I_(1))/(I_(2)) xx (M_(2))/(M_(1))) = sqrt(2 xx (1)/(sqrt2)) rArr T_(2)= (2^(5//4))/(2^(1//4))=2` sec