[amp_mcq option1=”Conservator” option2=”Breather” option3=”Bushings” option4=”Buchholz relay” correct=”option1″]
Transformers
22. The magnetising current of a transformer is usually small because it has
[amp_mcq option1=”small air gap” option2=”large leakage flux” option3=”laminated silicon steel core” option4=”fewer rotating parts” correct=”option3″]
Detailed SolutionThe magnetising current of a transformer is usually small because it has
23. Power transformers are generally designed to have maximum efficiency around
[amp_mcq option1=”no-load” option2=”half-load” option3=”near full-load” option4=”10% overload” correct=”option3″]
Detailed SolutionPower transformers are generally designed to have maximum efficiency around
24. Efficiency of a power transformer is of the order of
[amp_mcq option1=”100 per cent” option2=”98 per cent” option3=”50 per cent” option4=”25 per cent” correct=”option2″]
Detailed SolutionEfficiency of a power transformer is of the order of
25. Which winding in a transformer has more number of turns?
[amp_mcq option1=”Low voltage winding” option2=”High voltage winding” option3=”Primary winding” option4=”Secondary winding” correct=”option2″]
Detailed SolutionWhich winding in a transformer has more number of turns?
26. Which of the following properties is not necessarily desirable for the material for transformer core?
[amp_mcq option1=”Low hysteresis loss” option2=”High permeability” option3=”High thermal conductivity” option4=”Adequate mechanical strength” correct=”option3″]
27. Noise level test in a transformer is a
[amp_mcq option1=”special test” option2=”routine test” option3=”type test” option4=”none of the above” correct=”option2″]
28. In a transformer routine efficiency depends upon
[amp_mcq option1=”supply frequency” option2=”load current” option3=”power factor of load” option4=”both (B) and (C)” correct=”option4″]
Detailed SolutionIn a transformer routine efficiency depends upon
29. Star/star transformers work satisfactorily when
[amp_mcq option1=”load is unbalanced only” option2=”load is balanced only” option3=”on balanced as well as unbalanced loads” option4=”none of the above” correct=”option3″]
Detailed SolutionStar/star transformers work satisfactorily when
30. When secondary of a current transformer is open-circuited its iron core will be
[amp_mcq option1=”hot because of heavy iron losses taking place in it due to high flux density” option2=”hot because primary will carry heavy current” option3=”cool as there is no secondary current” option4=”none of above will happen” correct=”option1″]
Detailed SolutionWhen secondary of a current transformer is open-circuited its iron core will be