Question

A circular coil of wire is made up of 200 turns, each of radius 10 cm. If a current of 0.5A passes through it, what will be the Magnetic field at the centre of the coil?

Answer 1

Given:

N = 200 turns

R = 10 cm = 10 × 10⁻² m = 1 × 10⁻¹ m

I = 0.5 A = 5 × 10⁻¹ A

To find:

Magnetic field (B) at center of coil = ?

Formula:

`B_("center") = (mu_0 NI)/(2 R)`

∴ `B_("center") = (4 pi xx 10^-7 xx 200 xx 5 xx 10^-1)/(2 xx 1 xx 10^-1`

= 4 × 3.142 × 10⁻⁷ × 500

= 4 × 3.142 × 5 × 10⁻⁵ 

= 62.84 4 × 10⁻⁵ 

B_center = 6.284 × 10⁻⁴ Wb/m²