Electrical Machines Normally for the design of transformer the ambient temperature is taken as 45°C. 35°C. 32°C. 27°C. 45°C. 35°C. 32°C. 27°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines On switching a DC motor to DC supply mains, it is found to rotate in the direction opposite to that for which it is designed. The DC motor is Differentical compound. Series shunt. Cummulative compound. have an equal number of electrons and protons. Differentical compound. Series shunt. Cummulative compound. have an equal number of electrons and protons. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC Shunt Motor electromagnetic torque developed is Proportional to the armature current. Proportional to the square of armature current. Inversely proportional to the armature current. None of above. Proportional to the armature current. Proportional to the square of armature current. Inversely proportional to the armature current. None of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA 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 speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 920 RPM 960 RPM 970 RPM 940 RPM 920 RPM 960 RPM 970 RPM 940 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5 Ω and back emf of 200 V is 400 A. 40 A. 44 A. 440 A. 400 A. 40 A. 44 A. 440 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated) changes to three times the original value changes to 1.5 times the original value changes to 0.5 times the original value remain the same as the original changes to three times the original value changes to 1.5 times the original value changes to 0.5 times the original value remain the same as the original ANSWER DOWNLOAD EXAMIANS APP
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