A toroid of non ferromagnetic has core of inner radius `25cm` and outer radius `26cm`. It has 3500 turns `&` carries a current of `11A`, then find the magnetic field at a point
`(i)` In the internal cavity of toroid
`(ii)` At the midpoint of the windings
`(iii)` At a point which is at a distance of `30cm` from the centred of toroid.

Explanation

`i) B =0`
ii) ` B = (mu_0)/(2pi)("ni")/(r) = 2 xx 10^(-7) xx (3500 xx 11)/(51 xx 10^(-2)) xx 2`
` = 88/3 xx 10^(-3) = 26.3 xx 10^(-3) T`
iii) B= 0 Based on magnetism for solenoid and toroid.