Electrical Machines To eliminate 5th harmonic in the induced voltage phase breadth should be 36° 72° 30° 18° 36° 72° 30° 18° 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, 2, 3 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct 1, 2 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics the inequality of air-gap flux on the top and bottom halves of the armature is removed a counter-emf is induced in the coil undergoing commutation the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics the inequality of air-gap flux on the top and bottom halves of the armature is removed a counter-emf is induced in the coil undergoing commutation ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole DC generator runs at 750 rpm and generate an emf of 240 V. The armature is wave wound and has 792 conductors. If the total flux from each pole is 0.0145 Wb. What is the leakage co-efficient? 1.2. 1.5. 1.4. 1.8. 1.2. 1.5. 1.4. 1.8. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase slip-ring induction motor, brushes are connected to DC supply. equalizing coils. external star-connected resistors. 3 - Φ AC supply. DC supply. equalizing coils. external star-connected resistors. 3 - Φ AC supply. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a short circuit test on a transformer is performed at 25 V, 50 Hz, the drawn current is I1. If the test is performed by 25 V and 25 Hz and power drawn current is I2, then I1 < I2 I1 = I2 I1 > I2 None of these I1 < I2 I1 = I2 I1 > I2 None of these ANSWER DOWNLOAD EXAMIANS APP
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