Question

A closed coil consists of 500 turns has area 4 cm^2 and a resistance of 50 Omega. The coil is kept with its plane perpendicular to a uniform magnetic field of 0.2 Wb/m^2. Calculate the amount charge flowing through the coil if it is rotated through 180^@

Answer 1

The amount charge flowing through the coil if it is rotated through 180° is :

• Given : No. of turns in closed coil = 500

Area of rectangular frame = 4.0 cm^2

Resistance = 50 ohm

Magnetic field perpendicular to the coil = 0.2 wb/m^2

• Magnetic flux through coil, Φi = NBA

= 500×0.2×4×10^-4 = 0.04 weber

Φf ( when coil is rotated by 180° )

= -0.04 weber

• ∆Φ = 0.04 - (-0.04) = 0.08 weber

Induced charge, q = I×∆t

= ( ∆Φ/R∆t )×∆t = ∆Φ/R = 0.08/50

= 0.0016 C = 1.6×10^-3 C

• Hence charge flowing through coil = 1.6×10^-3 C