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)=2xx10^(-7)xx(3500xx11)/(51xx10^(-2))xx2`
`=(88)/(3)xx10^(-3)=29.3xx10^(-3)T`
`(iii) " "B=0` Bases on magnetism for solenoid and toroid.