Question

. You are an electrician on the job. It is decided that the speed of a large DC motor is to be reduced by connecting a resistor in series with its armature. The DC voltage applied to the motor is 250 V, and the motor has a full-load armature current of 50 A. Your job is to reduce the armature current to 40 A at full load by connecting the resistor in series with the armature. What value of resistance should be used, and what is the power rating of the resistor?

Answer 1

The value of resistance that should be used is 12.5 ohms. The power rating of the resistor should be 2,500 watts.

Step-by-step explanation: