As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit

Related MCQs

• The e.m.f. induced in the armature of a shunt generator is 600 V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be
• At the instant of starting when a D.C. motor is put on supply, it behaveslike
• In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to
• In D.C. generators, current to the external circuit from armature is given through
• Two D.C. shunt generators, each with armature resistance of 0.02 ohm and field resistance of 50 ohm run in parallel and supply a total current of 1000 amperes to the load circuit. If their e.m.fs. are 270 V and 265 V, their bus bar voltage will be
• In a D.C. shunt motor, under the conditions of maximum power, the current inthe armature will be
• The current drawn by the armature of D.C. motor is directly proportional to
• If I2 be the armature current, then speed of a D.C. shunt motor is
• Two generators A and B have 6-poles each. Generator A has wave wound armature while generator B has lap wound armature. The ratio of the induced e.m.f. is generatorA and B will be
• In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will