Magnetic field induction at the centre of a circular coil of radius 5 ~cm and carrying a current 0.9 ~A is (in SI units) ( ₀= . absolute permittivity of air in SI units, velocity of light =3 10^8 ~ms ⁻¹ )

Step-by-step solution

Magnetic field induction at the centre of circular coil, aligned & c^2= 1 ₀ ₀ & ₀= 1 ₀ c^2 & aligned So, from Eq. (i), we get aligned B & = 1 ₀ c^2 I 2 r & = 1 ₀ (3 10^8 )^2 0.9 2 5 10⁻² & = 1 9 ₀ 9 10¹⁶ = 1 ₀ 10¹⁶ aligned