Question

A torpid of mean radius 'c' cross section radius 'r' and total number of turns N. It carries a current 'i'. The torque experienced by the toroid if a uniform magnetic field of strength B is applied –

• A. Is zero
• B. Is BiNpr²
• C. Is BiNpa²
• D. Depends on the direction of magnetic field

Answer 1

Answer: (A)

Is zero

Answer 2

The resultant magnetic dipole moment of toroid is zero. $\mathrm { d } \vec { \mu }$ of small parts of toroid turn along a circle and hence there resultant is zero.