Tag: effects of electric current

An electric generator is a machine which generates electricity by using the principle of electromagnetic induction. It converts mechanical energy to electrical energy.

Electric generator is the application of EMI. The electric generator woeles on the principle that when a straight conductor is moved in magnetic field, then current is induced in the conductor.

AC generators are used in power station to generate electricity, which is supplied to our hours. AC generator is also h/a alternator.

AC generator means alternating generator. i.e. AC generator produces current that revenues its direction continuously.

When the plane of the rectangular coil is parallel to the magnetic field, angle between the magnetic field and the area vector of coil  $\theta = 90^o$
Flux passing though the coil  $\phi = BA \ \cos\theta = BA \ \cos90^o = 0$
Thus no emf is induced in the coil and induced current is zero.

The main difference  between $A.C$ generator and $D.C$ generator is carbon brushes.

Answer is D.

The emf is actually induced by a change in the quantity called the magnetic flux rather than simply by a change in the magnetic field. Magnetic flux is proportional to both the strength of the magnetic field passing through the plane of a loop of wire and the area of the loop. The value of the magnetic flux is proportional to the total number of lines passing through the loop. When the area is perpendicular, that is, at right angles (90 degrees) to the lines, the maximum number of lines passes through the area and the flux is a maximum. When the area is parallel to the lines, no lines pass through the area and the flux is 0.
Hence, maximum number of lines of force passes though the coil when the angle between the plane of coil and lines of force is 90 degrees.