Class 12 NEET Physics Magnetism and Matter Questions

(i) M=M1+M2
I=I1+I2
(ii) M=M1−M2
I=I1+I2
(i) Similar poles are placed at the same side (sum position)
(ii) Opposite poles are placed at the same side (difference position)
I1 and I2 are the moments of inertia of the magnets and M1 and M2 are the moments of the magnets.
Here M1=M and M2=2M,I1=I2=I (say), for same geometry.
For same position.
T1=2π√

I1+I2

(M1+M2)H

=2π√

2I

(M+2M)H

For difference position.
T2=2π√

I1+I2

(M2−M1)H

=2π√

2I

(2M−M)H

∴

T1

T2

=√

M

3M

=

1

√3

<1
∴ T1<T2