MHT CET202013 Oct 2020Morning ShiftPhysicsMagnetic Effects of CurrentActual
A circular coil of radius 'R' carries an electric current 'I'. The magnetic field due to the coil at a point on the axis of the coil located at a distance ' r ^ from the centre of the coil, such that r R , the magnetic field at that point is proportional to
Options
- A1 r³
- B1 r
- C1 r⁴
- D1 r²
Correct answer
A. 1 r³
Step-by-step solution
Magnetic field at a point on the axis of the coil is given by B = ₀ 4 2 M ( R ²+ r ² )^ 3 / 2 If r>>R then aligned & B= ₀ 4 2 M r³ & B 1 r³ aligned