Electrical Machines What is the necessity of copper brushes in a dc motors? To absorb the mechanical shocks produced during running condition. None of these. To increase the flux cutting by the rotor. To convert alternating supply current to direct current. To absorb the mechanical shocks produced during running condition. None of these. To increase the flux cutting by the rotor. To convert alternating supply current to direct current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In which of the following speed control of DC motor the speed obtained is below than the rated speed? Armature voltage control. Field resistance control. Any of above. Armature circuit resistance control. Armature voltage control. Field resistance control. Any of above. Armature circuit resistance control. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and the flux of a DC motor are held constant and voltage applied across its armature is increased by 5%, the speed of the motor will depend on other factors. remain unchanged. reduce by 5 %. increase by 5 %. depend on other factors. remain unchanged. reduce by 5 %. increase by 5 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, for the same value of Æ, Z and N; which one of the following statements is correct? Armature emf is same as long as the flux density in the air gap remains the same. Armature emf is more with wave winding than with lap winding. Armature emf depends on weather the machine is running as a motor or generator. Armature emf is less with wave winding than with lap winding. Armature emf is same as long as the flux density in the air gap remains the same. Armature emf is more with wave winding than with lap winding. Armature emf depends on weather the machine is running as a motor or generator. Armature emf is less with wave winding than with lap winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which type motors are preferred for lathes? Squirrel Cage induction motor. Synchronous motor. Either A or B. DC shunt motors. Squirrel Cage induction motor. Synchronous motor. Either A or B. DC shunt motors. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In double cage induction motor, the inner cage offers low resistance and low reactance. high resistance and low reactance. low resistance and high reactance. high resistance and high reactance. low resistance and low reactance. high resistance and low reactance. low resistance and high reactance. high resistance and high reactance. ANSWER DOWNLOAD EXAMIANS APP
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