What is armature reaction How does it affect the operation of a DC machine?

Definition: The armature reaction simply shows the effect of armature field on the main field. In other words, the armature reaction represents the impact of the armature flux on the main field flux. The armature field is produced by the armature conductors when current flows through them.

What is armature reaction and how does it affect the performance of machine?

Armature reaction is the effect on the main field flux of that flux set up by the currents in the armature winding. The effect is the same for both lap- and wave-wound machines.

What is armature reaction explain two effects of armature reaction in case of DC machines?

The armature reaction is the effect of the armature flux on the main flux. In case of a DC motor the resultant flux is strengthened at the leading pole and weakened at the trailing pole tips.

What is the effect of armature reaction on the main pole flux of a DC generator?

Explanation: The armature reaction flux strengthens each main pole at one end and weakens it at the other end (cross magnetizing effect).

What effect does armature reaction have on the torque speed characteristic of a shunt DC motor?

The change in armature current and torque on supplying load is graphically shown below. This increase in the amount of torque increases the speed and thus compensating for the speed loss on loading. Thus the final speed characteristic of a DC shunt motor, looks like.

How does the armature reaction affect the output voltage in a separately excited DC generator?

As the armature load current increases, the terminal voltage will decrease linearly. The terminal voltage of the separately excited DC generator would be expected to decrease in a linear manner due to the voltage drop across the armature circuit resistance.

What is the effect of armature flux on the main field?

Explanation: The armature reaction flux strengthens each main pole at one end and weakens it at the other end (cross magnetizing effect). Armature reaction with axis at 90° to the main field axis is known as cross-magnetizing mmf.