Study of DC Motor 
1. The speed of the dc motor can be increased by
2. The armature voltage control of dc motor provides
3. A direct on line starter is used for starting a motor up to
4. A 120 V shunt generator running at 850 rpm has its armature and shunt field resistance of 0.15 Ω and 50 Ω respectively. It supplies 200 lamps each rated as 60 W, 100 V. The friction, windage and core loss of the machine is 400 W. Its armature copper loss on full load and shunt field loss are
5. If A is the number of parallel paths and P is the number of poles of a dc motor, then the number of parallel paths in lap winding and wave winding are
6. If the armature current of a dc series motor has become twice, then the torque will become
7. If Eb is the back e.m.f. of a dc motor and V is the terminal voltage, then the condition for maximum power is
8. Which motor is not suitable for the application of centrifugal pumps?
9. The torque constant (Km), of a permanent magnet dc motor is 0.25 V sec / radian and armature resistance is 2 Ω. If the applied armature voltage is 90 V, then its zero speed torque is
10. Permanent magnet dc motors are extensively used in
11. DC series motors are used in electric traction. What happens to the speed and current of a dc motor if there is a sudden drop in the mains voltage?
12. The control of the dc motor is applied at the ______