Two origin-centered circular rings have radii a and b a and I_b. A narrow insulating rod coincident with their common diameter permits the smaller ring to rotate freely inside the larger ring. Show that the torque which must be applied to hold the planes of the rings at a right angle has magnitude.

Transcribed Image Text:

I b² 3b N == Molalb ola bob [1 - (²36)²]. a 4a