In a D.C. motor constant torque is produced due to? Mark as favorite Copy Link rotor laminations end-plates pole shoes commutator Check Answer
As the load is increased the speed of dc shunt motor will? Mark as favorite Copy Link reduce slightly increase slightly increase proportionately remains unchanged Check Answer
If conditions for maximum power for a D.C. motor are established, the efficiency of the motor will be? Mark as favorite Copy Link less than 50% 60 to 70% 80 to 90% 100% Check Answer
D.C. generators are normally designed for maximum efficiency around? Mark as favorite Copy Link full-load rated r.p.m. rated voltage all of the above Check Answer
Which of the following loss of D.C. motor decreases with increase in load? Mark as favorite Copy Link Friction and windage loss Core Loss Brush contact loss none of the above Check Answer
What is the effect produced by the electric current in an electric motor? Mark as favorite Copy Link Heating effect only Magnetic effect only Heating as well as magnetic effect Heating as well as chemical effect Check Answer
The mechanical power developed by a D.C. motor is equal to? Mark as favorite Copy Link power input + losses back e.m.f x armature current power output x losses power output x efficiency Check Answer
The use of armature divertor in rheostatic method of speed control for a D.C. shunt motor makes the method? Mark as favorite Copy Link less expensive less wasteful suitable for rapidly changing loads unsuitable for changing loads Check Answer
Which of the following methods is most effective in finding out the no load losses in a large D.C. shunt motor? Mark as favorite Copy Link Field's test Ward-Leonard test Block rotor test Swinburne's test Check Answer
Which D.C. motor is preferred for elevators? Mark as favorite Copy Link Shunt motor Series motor Differential compound motor Cumulative compound motor Check Answer