Electrical Machines With the increase in speed of a DC motor back emf increases but line current falls. back emf falls and line current increases. both back emf as well as line current fall. both back emf as well as line current increase. back emf increases but line current falls. back emf falls and line current increases. both back emf as well as line current fall. both back emf as well as line current increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator the actual flux distribution depends upon size of air gap. clearance between tips of the adjacent pole shoes. all of above. shape of the pole shoe. size of air gap. clearance between tips of the adjacent pole shoes. all of above. shape of the pole shoe. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A voltmeter gives 120 oscillations per minute when connected to the rotor of an induction motor. The frequency is 50Hz. The slip of the motor is 5% 4% 25% 2% 5% 4% 25% 2% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the armature current of 5 Amp is flowing through the dc motor the torque produced is 47 Nm. Keeping the speed constant if the armature current is increased to 7 amp, calculate the new torque. Assume losses to be constant. 74 Nm. 65.8 Nm. 27.73 Nm . 38.5 Nm. 74 Nm. 65.8 Nm. 27.73 Nm . 38.5 Nm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Magnetic field of a DC generator is produced by what? Electromagnets. Both B and C. None of the options. Permanent magnets. Electromagnets. Both B and C. None of the options. Permanent magnets. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor the 7th harmonic torque may make the motor rotate at (1 / 7)th synchronous speed. This is called resonance. cogging. harmonics. crawling. resonance. cogging. harmonics. crawling. ANSWER DOWNLOAD EXAMIANS APP