COMEDK2013PhysicsMagnetic Properties of Matter
A vertical circular coil of radius 0.1 ~m and having 10 turns carries a steady current. When the plane of the coil is normal to the magnetic meridian, a neutral point is observed at the centre of the coil. If B_ H =0.314 10⁻⁴ ~T , the current in the coil is
Options
- A0.5 ~A
- B0.25 ~A
- C2 ~A
- D1 ~A
Correct answer
A. 0.5 ~A
Step-by-step solution
Given, R=0.1 ~m , N=10, B_ H =0.314 10⁻⁴ ~T For neutral point, the magnetic field at the centre of coil carrying current is equal to the horizontal component of earth's field. i.e. aligned B_ H &= ₀ N I 2 R I &= 2 B_ H R ₀ N &= 2 0.314 10⁻⁴ 0.1 4 10⁻⁷ 10 &= 0.314 10⁻⁴ 2 3.14 10⁻⁷ 100 =05 ~A aligned