Electrical Machines The field divertor resistance for a DC series motor is of order of 50 Ω 10 Ω 0.1 Ω 100 Ω 50 Ω 10 Ω 0.1 Ω 100 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 67.5% 78.5% 82.5% 72.5% 67.5% 78.5% 82.5% 72.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the commutator pitch? The distance between the staring of first coil and its next successive coil Number of conductors spanned by one coil at the front end of the armature. Number of conductors spanned by one coil at the back end of the armature. Number of commutator segments between two successive coils. The distance between the staring of first coil and its next successive coil Number of conductors spanned by one coil at the front end of the armature. Number of conductors spanned by one coil at the back end of the armature. Number of commutator segments between two successive coils. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole dc motor with armature winding resistance of 0.6 ohm receives a supply of 230 Volt. If the back emf produced during running condition is equal to 210 volt. Calculate the current flowing through the armature at this point. 44.47 Amp. 43 Amp. 29 Amp. 33.33 Amp. 44.47 Amp. 43 Amp. 29 Amp. 33.33 Amp. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Thin laminations are used in a machine in order to reduce Eddy current losses Hysteresis losses Both 1 and 2 Copper losses Eddy current losses Hysteresis losses Both 1 and 2 Copper losses ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A Shunt generator running at 1000 rpm has generated emf of 100 V. If the speed increases to 1200 rpm, the generated emf will be nearly 140 V 120 V 175 V 240 V 140 V 120 V 175 V 240 V ANSWER DOWNLOAD EXAMIANS APP
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