At a certain place a magnet makes 30 oscillations per minute. At another place where the magnetic field is double, its time period will be

Options

A. 4 sec
B. 2 sec
C. 1/2 sec
D. `sqrt2` sec

Answer

D

Explanation

`T= 2pi sqrt((I)/(MB)), (T_(1))/(T_(2))= sqrt((B_(2))/(B_(1))) = sqrt((2B)/(B))= sqrt2`
`rArr T_(2)= (T_(1))/(sqrt2)= (2)/(sqrt2) = sqrt2` sec
as `T_(1) = (1)/(f_(1))= (1)/(30) xx 60= 2` sec