Electrical Machines Hopkinson test is conducted under which of the following condition? full load no load any of the above half load full load no load any of the above half load ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed regulation of a DC motor is given as (NnL − NfL)/NfL. NnL/NfL. NnL − NfL. (NfL − NnL)/NnL. (NnL − NfL)/NfL. NnL/NfL. NnL − NfL. (NfL − NnL)/NnL. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole wave wound dc motor having flux per pole of 9.56 X 10-3 Wb contains 460 armature conductors. Calculate the back emf produced when it is running at a speed of 1500 rpm. 220 volt. 440 volt. 240 volt. 230 volt. 220 volt. 440 volt. 240 volt. 230 volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 1 and 4 are correct 2, 3 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct 2, 3 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Unbalance 3 - Φ stator currents cause double frequency currents in the rotor. heating of rotor. All of these vibrations. double frequency currents in the rotor. heating of rotor. All of these vibrations. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 25 Hz. 16.67 Hz. 50 Hz. 60 Hz. 25 Hz. 16.67 Hz. 50 Hz. 60 Hz. ANSWER DOWNLOAD EXAMIANS APP
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