1. No –load test on a transformer is carried out to determine
- Copper loss
- Magnetizing current
- Magnetizing current and no-load loss
- Efficiency of the transformer
Answer: 3
2. The main purpose of performing open –circuit test on a transformer is to measure its
- Cu loss
- Core loss
- Total loss
- Insulation resistance
Answer: 2
3. During short –circuit test, the iron lose of a transformer is negligible becauseer is to measure its
- The entire input is just sufficient to meet Cu losses only
- Flux produced is a small fraction of the normal flux
- Iron core becomes fully saturated
- Supply frequency is held constanton resistance
Answer: 2
4. In operating a 400 Hz transformer at 50 Hz
- Only voltage is reduced in the same proportion as the frequency
- Only KVA rating is reduced in the same proportion as the frequency
- Both voltage and KVA rating are reduced in the same proportion as the frequency
- None of the above
Answer: 2
5.Transformer are rated in KVA instead of KW because
- Load power factor is often not known
- KVA is fixed whereas KW depends on load p.f.
- Total transformer loss depends on volt-ampere
- It has become customary
Answer: 3
Also Read:
Resistance in series and parallel connection
6. What is Transformer?
- Transformer is a device used to convert low alternating voltage to a high alternating voltage
- Transformer is a device used to convert alternating current to direct current
- Transformer is a device used to convert low alternating current to a high alternating current
- Transformers are used only for low alternating voltage
Answer: 1
7. Transformer ratings are given in _____________
- kVA
- HP
- kVAR
- kW
Answer: 1
8. What is the current transformer?
- transformer used with an A.C. voltmeter
- transformer used with an A.C. ammeter
- transformer used with an D.C. voltmeter
- transformer used with an D.C. ammeter
Answer: 2
9. Current transformers are _______________
- parallel connected type of instrument transformers
- series connected type of instrument transformers
- parallel connected normal transformers
- series-parallel connected type of instrument transformers
Answer: 2
10. Which of the following is not a part of transformer installation?
- Breather
- Conservator
- Exciter
- Buchholz relay
Answer: 3
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