Electrical Machines The material used for commutator brushes is mostly copper. mica. carbon. cast iron. copper. mica. carbon. cast iron. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing diverter resistance of a DC series motor causes decrease in speed demanding less armature current. increase in speed but armature currnet remains the same. decrease in speed but armature current remains the same. increase in speed demanding more armature current. decrease in speed demanding less armature current. increase in speed but armature currnet remains the same. decrease in speed but armature current remains the same. increase in speed demanding more armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The result of slip test on a 3-phase, 20 KVA, 400 V, 50 Hz connected salient pole alternator is given below- Phase value: Vmax = 100 V, Vmin = 96 V, Imax = 10 A and I min = 7 A. The direct and quadranature axis reactances are respectively 14.28 and 5.54 Ω. 8.248 and 9.60 Ω. 8.248 and 5.54 Ω. 14.28 and 9.60 Ω. 14.28 and 5.54 Ω. 8.248 and 9.60 Ω. 8.248 and 5.54 Ω. 14.28 and 9.60 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If a shunt generator delivers 100 A at 200 V, and the resistances of the shunt field and armature are 100 ohms and 0.01 ohms respectively, the generator emf will be no resistance is connected. series. any one of the connection. parallel. no resistance is connected. series. any one of the connection. parallel. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Pole changing methods are suitable only for ___________ type induction motor. wound. cage. none of these. linear. wound. cage. none of these. linear. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor has a rotor resistance of 0.002 Ω / phase. If the resistance is increased to 0.004 Ω / phase then the maximum torque will increase by 200% remain unaltered increase by 100% reduced to half increase by 200% remain unaltered increase by 100% reduced to half ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS