Q: A vibration magnetometer consists of two identical bar magnets placed one over the other such that they are perpendicular and bisect each other. The time period of oscillation in a horizontal magnetic field is 2(5/4) sec. One of the magnets is removed and if the other magnet oscillates in the same field, then the time period in seconds is:
Sol: When two identical bar magnets are held perpendicular to each other.
; I1 = I
T1 = 2(5/4) sec ; T2 = ?
M2 = M (as one magnet is removed)
I2 = I/2
T2 = 2 sec