Question

Each of the two identical magnets and suspended alone makes 30 oscillations per minute at a place. The number of oscillations per minute if they are fixed at right angle and allowed to oscillate in the same field will be approximately

25 oscillation/ min
30 oscillation/ min
60 oscillation/ min
15 oscillation/ min​

Answer 1

Answer:

15 oscillation/min answer

Answer 2

Given: Two identical magnets suspended alone makes 30 oscillations per minute at a place

To find: number of oscillations per minute if they are fixed at a right angle and allowed to oscillate in the same field

Solution: We are given that the magnetic moment of both the magnet is the same

so M1 = M2 and I1= I2

here M is the magnetic moment and I is a moment of inertia of the magnet

Also, T1= T2 = 60/30 = 2sec

that is time period

After fixing it with each other at the right angle we can get the net magnetic moment as Mnet= √2M, Inet = 2I

we need to find a new T

T= 2π√( I/MB)

here I is a moment of inertia, M is the magnetic moment, B is the magnetic field

T1/T2 = √( I/2I × √2M/M ) = 1/(2)^1/4

T2 = 2.2^1/4 = 2^5/4

Number of oscillation per minute= 60/ 2^5/4 = 25

Therefore, a number of oscillations per minute if they are fixed at a right angle and allowed to oscillate in the same field will be a) 25 oscillation/ min.