A DC shunt motor is excited from voltage source and its brush axis rotated by an angle 'α' from the geometrical neutral axis. The torque developed will be proportional to:
- A. sin α
- B. cos α
- C. tan α
- D. cos 2α
Answer: B. cos α
Explanation: Shifting the brush axis by angle α from the GNA reduces effective mutual flux linkage and armature torque by a factor of cos α.