The earth's magnetic field at a given point is 0.5 10⁻⁵ ~Wb / m ^2 . This field is to be annulled by magnetic induction at the center of a circular conducting loop of radius 5.0 ~cm . The current required to be flown in the loop is nearly

Step-by-step solution

The magnetic field at the centre of a circular loop carrying current I is given by B= m₀ I 2 r where r is the radius of the circular loop. Given that r=5.0 ~cm =0.05 ~m . Now, B= ₀ I 2 r =0.5 10⁻⁵ aligned I & = 0.5 10⁻⁵ 2 0.05 ₀ = 0.5 10⁻⁵ 0.1 4 10⁻⁷ & =0.3978 0.4 Å aligned