Question

A wheel with 8 metallic spokes is 50 cm long is rotated with a speed of 120 revolution per minute in a plane normal to the horizontal component of the earth magnet

Answer 1

Hey !!

H = Bcos θ = 0.4 cos 60°

              = 0.2 G = 0.2 × 10⁻⁴ T

This component is parallel to the plane of the wheel.

Thus, the emf induced is

              ε = 1/2 Bl²ω where, ω = 2πf

             ε = 1/2 × 0.2 × 10⁻⁴ × (0.5)² × 2 × 3.14 × 120 / 60

           ∴         ε = 3.14 × 10⁻⁵ V ( FINAL RESULT )

GOOD LUCK !!