explain the characteristics of a d.c. motor when series-and seperately- excited.?

Question

the d.c. motor consists of an armature and field winding, there is no permanent magnet present. a supply voltage of 12V was used with max current of 3A.

Answer 1

The armature rotates when voltage is applied. The current increases as the load on the motor increases. The strength of the motor depends on the size of the armature, the size of the output shaft and the strength of the field winding. Higher voltage will give you more power but you can easily burn out the armature winding and field winding if the voltage and load get too high.