Q1. What is the frequency of rotation of 1000 loop coil of area 20cm2 in a magnetic field of 5T to

generate an emf that has a maximum value of 15.7V?

Emf e generated in a coil with no of turn n and area A rotating in a magnetic field B with angular speed of ω is given by the expression

e = e₀ sinωt

where e₀ = nωAB which is the maximum emf generated

Putting the given values

15.7 = 1000xω x 20 x 10⁻² x 5

ω =.0157

frequency of rotation

= ω / 2π

=.0157 / 2 x 3.14

=.0025 / s

9 rotation / hour.