Virtual Labs

a: Dissipates energy in armature circuit b: Dissipates energy in field circuit c: Both a and b d: Supply energy to source

a: It will start revolving in other direction at low speed b: Motor will stop c: Motor will burn d: None of these

a: That speed above normal speed can be achieved b: That commutation becomes unsatisfactory c: Its low efficiency d: None of these

a: A.C. excitation to the field of the motor b: Variable excitation to the field of the motor c: Constant excitation to the field of the motor d: No excitation to the field of the motor

a: Increased maintenance cost b: Its high initial cost c: Its low efficiency at light loads d: All of the above

Speed Control of DC motor by field resistance control