Question

How speed of the DC shunt motor can be increased?

(a) Decreasing the field current

(b) Increasing the field current

(c) Decreasing the load current

(d) Increasing the armature current

I have been asked this question in quiz.

I want to ask this question from Operating Characteristics of DC Shunt Motor -1 in chapter Characteristics of DC Motors of DC Machines

Answer 1

Right choice is (b) Increasing the field current

Easiest explanation: For a constant load, load current will remain constant. Decreasing armature current will help in increasing speed for DC shunt motor. Since load current is addition of armature current and field current we’ll get less armature current for more field current.