| 1. | If the input to the prime mover of an alternator is kept constant but the excitation is increased, then ? | |
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KVA will be lagging
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kVA will be leading
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kW will be changed
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the power factor of the load remains constant
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Report Question| 2. | Which of the following organisations is engaged in the manufacture of large size alternators for power plants in India ? | |
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Department of Science and Technology
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Electricity Authority of India
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National Thermal Power Corporation Ltd
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Bharat Heavy-Electricals Ltd.
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| 3. | Salient pole type alternators are generally used on ? | |
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low voltage alternators
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hydrogen cooled prime movers
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high speed prime movers
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low and medium speed prime movers
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| 4. | When a three-phase alternator supplies capacitive load, armature reaction flux will be ? | |
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opposing the main magnetic field
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helping the main magnetic field
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either (a) or (b)
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none of the above
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| 5. | In an alternator, for a coil having a span of 2/3 of pole pitch, the coil span factor will be ? | |
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0.866
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0.707
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0.6
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0.2
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| 6. | Damper winding on alternator results in all of the following except ? | |
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increases instability of machine
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elimination of harmonic effects
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absorption of energy of oscillations when operating in parallel with other alternators
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suppression of spontaneous hunting when supplying power to transmission line with high resistance to reactance ratio
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| 7. | ln an alternator terminal voltage rise will be more ? | |
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when leading load is thrown off
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when lagging load is thrown off
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when unity power factor load is thrown off
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none of the above
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| 8. | ln an alternator, armature reaction is considered equivalent to ? | |
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fictitious impedance
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fictitious conductance
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fictitious reactance
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fictitious resistance
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| 9. | Two alternators are to be put in parallel. Which of the following factors should be identical for both ? | |
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Frequency
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Phase sequence
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Voltage
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All of the above
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| 10. | As load power factor of an alternator becomes more leading, the value of generated voltage required to give rated terminal voltage ? | |
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decreases
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increases
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varies with rotor speed
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remains unchanged
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