Question

The diagram of a D.C generator and the description on how it works?

Answer 1

DC Generator

Diagram is in attachment

Principle

=>ELECTROMAGNETIC INDUCTION

Structure

When current flows continuously in one

direction the current is referred to as Direct current. To obtain such a DC Generator, the AC generator is modified by replacing the slip rings with a commutators(half slip rings) or split rings.

Working

=>let the generator coil ABCD be initially in the horizontal position. Let the coil be rotated in an anti-clockwise direction as shown in figure then side AB downward and side CD Upward. According to flemmings right had rule, the induced current flows in the direction of BA in the side AB and in direction DC in the side CD. Thus the induced current flows in the direction of DCBA during it's first half of rotation.

After half rotations, arms AB and CD interchange their position. Whem the coil interchanged their position, the Split rings automatically change their contact with carbon brushes. Due to this the current in the load remains in one direction and thus B1 remains positive and B2 remains negetive.

Thanks

Answer 2

Working Principle Of A DC Generator:

According to Faraday’s laws of electromagnetic induction, whenever a conductor is placed in a varying magnetic field (OR a conductor is moved in a magnetic field), an emf (electromotive force) gets induced in the conductor. The magnitude of induced emf can be calculated from the emf equation of dc generator.If the conductor is provided with a closed path, the induced current will circulate within the path. In a DC generator, field coils produce an electromagnetic field and the armature conductors are rotated into the field. Thus, an electromagnetically induced emf is generated in the armature conductors. The direction of induced current is given by Fleming’s right hand rule.According to Fleming’s right hand rule, the direction of induced current changes whenever the direction of motion of the conductor changes. Let’s consider an armature rotating clockwise and a conductor at the left is moving upward. When the armature completes a half rotation, the direction of motion of that particular conductor will be reversed to downward. Hence, the direction of current in every armature conductor will be alternating.