Q: Two bar magnets placed together in a vibration magnetometer take 3 seconds for 1 vibration. If one magnet is reversed, the combination takes 4 seconds for 1 vibration. Find the ratio of their magnetic moments.

Sol: Given that, T_{1} = 3 s and T_{2} = 4 s

$\large \frac{M_1}{M_2} = \frac{T_2^2}{T_1^2}$

$\large \frac{M_1}{M_2} = \frac{4^2 + 3^2 }{4^2 -3^2 }$

$\large \frac{M_1}{M_2} = \frac{16+9}{16 -9} = \frac{25}{7}$

= 3.57