Electrical Machines The material used for commutator brushes is mostly copper. carbon. mica. cast iron. copper. carbon. mica. cast iron. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 1, 3 1, 4 2, 3 2, 4 1, 3 1, 4 2, 3 2, 4 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 reduce by 5 %. remain unchanged. depend on other factors. increase by 5 %. reduce by 5 %. remain unchanged. depend on other factors. increase by 5 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature coil is short circuited by brushes when it lies along field axis. in none of above positions. in any of above positions. along neutral axis. along field axis. in none of above positions. in any of above positions. along neutral axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When an electric train is moving down a hill, the DC motor will operate as DC shunt generator. DC shunt motor. DC series generator. DC series motor. DC shunt generator. DC shunt motor. DC series generator. DC series motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following load normally needs starting torque more than rated torque? Centrifugal pumps. Conveyers. Blowers. Air compressors. Centrifugal pumps. Conveyers. Blowers. Air compressors. ANSWER DOWNLOAD EXAMIANS APP
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