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The flash point of transformer oil should be higher than_______________?
Related MCQs
The usual values of maximum flux densities for distribution transformers using hot rolled silicon steel are__________?
For large power transformers, self oil cooled type or air blast type which of the following values of current density may be used?
A practical formula for determining the thickness of insulation between low voltage and high voltage windings is__________?
The surge phenomenon is particularly important in case of__________?
The insulation between windings and grounded core and the insulation between the windings of the same phase is called__________?
__________ is the common method of applying brushes to the commntator?
__________ brushes are fragile and cause excessive wear of commutator?
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D.C. servomotors are used in__________?
The cylindrical windings using circular conductors are used for current rating of__________?
Which of the following in an application of D.C. motors?
The stator of a D.C. machine comprises of__________?
is usually used for brush rockers__________?
Which of the following brushes can be used for high values of current density ?
Which of the following problem arises in D.C. motors which are fed from thyristor bridge circuits ?
In a D.C. machine the number of brush arms is _________ the number of poles?
D.C. machines designed with a large value of air gap length have__________?
In D.C. machines the usual limit of slot pitch is__________?
The operation of a D.C. machine with large air gap lengths is comparatively__________?
In D.C. machines, ir order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made__________?
In a D.C. machine, the value of peripheral speed should not, normally, exceed__________?
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In a D.C. machine the current per brush arm should not be more than__________?
In D.C. machines the width of the duct is usually__________?
In D.C. machines, the ________ in field mmf results in increase in size and cost of machines?
Which of the following methods may be adopted to reduce the effects of armature reaction ?
In D.C. machines the number of slots per pole usually lies__________?
In transformers using hot rolled steel, the cross-section of the yoke is made about __________ greater than that of the core?
Power transformers have rating__________?
__________are always double layer type?
The winding where dummy coils are used is sometimes called__________?
When the two coil sides forming a coil are spaced exactly one pole pitch apart they are said to be of__________?
The distance between the starts of two consecutive coils measured in terms of coil sides is called__________?
Dummy coil should not be used in__________?
Power transformers should be designed to have maximum efficiency__________?
Yokes with rectangular cross-section are used for__________?
Which of the following methods is most accurate ?
__________are used for construction of core of electromagnets?
Tractive magnets are operated from__________?
Which of the following is the commonly used type of electromagnets ?
The design of electromagnets is based upon which of the following fundamental equations ?
electromagnets generally function as holding magnets ?
By which of the following methods motor rating for variable load drives can be determined ?
The value of exciting or magnetizing current depends upon which of the following factors ?
By which of the following methods the temperature rise of windings and other parts may be determined ?
Which of the following methods is used for air cooling of turbo-alternators ?
The slot leakage can be calculated by making which of the following assumptions ?
Which of the following methods does not take into account the maximum temperature rise under variable load conditions ?
The time taken by the machine to attain 0.632 of its final steady temperature rise is called__________?
With direct water cooling it is possible to have ratings of about__________?
In self cooled motors the cooling time constant is about __________ than the heating time constant because cooling conditions are worse at standstill?
The flash point of transformer oil should be higher than_______________?
A. 40°C
B. 60°C
C. 80°C
D. 104°C
Correct Answer:
104°C
✔
Last Updated:
December 22, 2018