Question

In a $DC$ generator, the induced $e.m.f$ in the armature is

• A. $DC$
• B. $AC$
• C. fluctuating $DC$
• D. both $AC$ and $DC$

Answer 1

The correct option is B

$AC$

1. A rectangular coil is situated between the magnetic field and the split ring commutator in an electric generator, and as $AC$ current flows through the coil from the split ring commutator, a torque operates on the coil, rotating it continually.
2. The split ring device is used to reverse the current at that point and maintain the direction of the current in the external circuit to flow in the same direction as $DC$ current to keep the torque from reversing every time the coil moves through the plane perpendicular to the magnetic field according to Fleming's right hand thumb rule.
3. The split ring commutator is made up of two copper rings that are held apart in the middle to prevent them from touching. They have the appearance of a copper ring with a split in the middle. As a result, it's known as a split ring armature.

Therefore, In a $DC$ generator, the induced $e.m.f$ in the armature is $AC$.

Hence, the option $B$ is correct.