Question

Imagine that you are producing small AC generators (dynamo] for bicycles. What factors that you keep in mind to get maximum induced emf out of the generators th produce?​

Answer 1

The magnitude of induced e.m.f. is maximum, when the plane of the armature of a.c. dynamo is:

When the plane of the armature is parallel to the lines of force of magnetic field, the rate of change of magnetic flux linked with it is maximum. Therefore, the e.m.f. induced in the armature in this orientation is maximum.

Answer 2

Given :

Ac generator for bicycle.

To find :

Factors to get maximum induced emf.

Solution :

According to Faraday 's law :

Induced emf :

$\epsilon = -N\frac{d\phi }{dt}$

where

Φ = The flux through Coil.

N = Number of turns of loop.

t = Time.

ϵ= EMF induced.

On putting the values of flux change with respect to time in above equation, we get :

$\epsilon = NBAsin \theta \: \frac{d \theta}{dt}$

Where

B = magnetic field provided to coil.

A= Area through which flux change.

θ = Angle between Area vector and Magnetic field.

As

$\\ \bf \frac{d \theta}{dt} \: = \omega \\ \theta = \omega \: t$

So

$\epsilon = NBA \omega \: sin ( \omega \: t)$

In this case to get the maximum emf :

The higher the number of coils,

The larger the area and

The stronger the magnetic field,

The emf induced will be greater.

In all these fixed values

Maximum value of sin(ωt)= 1.

As

θ=ωt

So, To get the Maximum value of EMF induced

sin (θ)= 1

θ= 90°

So the area vector and magnetic field vector must be

perpendicular to get the maximum EMF.