A. mica strip
B. thin coat of varnish
C. paper
D. any of the above
Correct Answer: thin coat of varnish ✔
Last Updated: September 29, 2021
Related MCQs
- Which of the following statements regarding an idel single-phase transformer having a turn ratio of 1 : 2 and drawing a current of 10 A from 200 V A.C. supply is incorrect?
- In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are__________?
- Losses which occur in rotating electric machines and do not occur in transformers are__________?
- For given applied voltage, with the increase in frequency of the applied voltage?
- In a power or distribution transformer about 10 per cent end turns are heavily insulated__________?
- Reduction in core losses and increase in permeability are obtained with transformer employing__________?
- The noise produced by a transformer is termed as__________?
- Which of the following parts of a transformer is visible from outside ?
- Which of the following insulating materials can withstand the highest temperature safely ?
- The efficiency of two identical transformers under load conditions can be determined by__________?
- Which of the following acts as a protection against high voltage surges due to lightning and switching ?
- A good voltage regulation of a transformer means__________?
- Which of the following protection is normally not provided on small distribution transformers ?
- For a transformer, operating at constant load current, maximum efficiency will occur at__________?
- A Transformer transforms__________?
- A transformer can have regulation closer to zero__________?
- In a transformer the resistance between its primary and secondary should be__________?
- The secondary of a current transformer is always short-circuited under operating conditions because it__________?
- A shell-type transformer has_________?
- N atural air coo ling is generally restricted for transformers up to__________?
- The size of a transformer core will depend on__________?
- The secondary winding of which of the following transformers is always kept closed?
- The function of breather in a transformer is__________?
- The efficiencies of transformers compared with that of electric motors of the same power are__________?
- The transformer oil should have ___ volatility and _______ viscosity?
- In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of__________?
- For the parallel operation of single phase transformers it is necessary that they should have__________?
- Minimum voltage regulation occurs when the power factor of the load is__________?
- Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is__________?
- Short circuit test on transformers is conducted to determine__________?
- If a transformer is switched on to a voltage more than the rated voltage__________?
- Open circuit test on transformers is conducted to determine__________?
- Part of the transformer which is most subject to damage from overheating is__________?
- During open circuit test of a transformer:
- The voltage transformation ratio of a transformer is equal to the ratio of__________?
- A no-load test is performed on a transformer to determine__________?
- Which type of winding is used in 3 phase shell-type transformer?
- An open-circuit test on a transformer is conducted primarily to measure__________?
- When secondary of a current transformer is open-circuited its iron core will be__________?
- The efficiency of a transformer, under heavy loads, is comparatively low because__________?
- The maximum load that a power transformer can carry is limited by its__________?
- The hum in a transformer is mainly attributed to__________?
- Which of the following is the most likely source of harmonics in a transformer ?
- If a transformer is continuously operated the maximum temperature rise will occur in__________?
- Iron loss of a transformer can be measured by__________?
- Which of the following loss in a transformer is zero even at full load __________?
- Negative voltage regulation is indicative that the load is__________?
- Helical coils can be used on__________?
- If the supply frequency to the transformer is increased,”the iron loss will__________?
- Which of the following is not a routine test on transformers ?
- An ideal transformer will have maximum efficiency at a load such that?