Electrical Machines A 4 pole dynamo with wave wound armature has 51 slots contains 20 conductors in each slot. If induced emf 357 Volts and speed is 8500 rpm, flux per pole will be 1.4 mWb. 2.7 mWb. 1.2 mWb. 3.5 mWb. 1.4 mWb. 2.7 mWb. 1.2 mWb. 3.5 mWb. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator the actual flux distribution depends upon size of air gap. shape of the pole shoe. all of above. clearance between tips of the adjacent pole shoes. size of air gap. shape of the pole shoe. all of above. clearance between tips of the adjacent pole shoes. 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, 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 1 and 4 are correct 2, 3 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines On which of the following factor/factors the speed of a DC motor depends upon? Field flux. Armature current. Applied voltage. All of these. Field flux. Armature current. Applied voltage. All of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is reduced, the power factor is unity power factor lagging power factor None of these leading power factor unity power factor lagging power factor None of these leading power factor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous machine, if φ is the flux per pole and f is the frequency of the emf induced E then E ∝ φf E ∝ 1/(φf) E ∝ f/φ E ∝ φ/f E ∝ φf E ∝ 1/(φf) E ∝ f/φ E ∝ φ/f ANSWER DOWNLOAD EXAMIANS APP
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