Natural oil cooling is used for transformers up to a rating of
Natural oil cooling is used for transformers up to a rating of
The secondary of a current transformer is always short-circuited under operating conditions because it
The secondary of a current transformer is always short-circuited under operating conditions because it
A shell-type transformer has
A shell-type transformer has
The complete circle diagram of induetion motor can be drawn with the help of data found from
The complete circle diagram of induetion motor can be drawn with the help of data found from
A transformer can have zero voltage regulation at
A transformer can have zero voltage regulation at
The efficiency of a transformer, under heavy loads, is comparatively low because
The efficiency of a transformer, under heavy loads, is comparatively low because
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?
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?
The noise produced by a transformer is termed as
The noise produced by a transformer is termed as
The maximum efficiency of a distribution transformer is
The maximum efficiency of a distribution transformer is
Power transformers are generally designed to have maximum efficiency around
Power transformers are generally designed to have maximum efficiency around
The magnetising current of a transformer is usually small because it has
The magnetising current of a transformer is usually small because it has
Transformer breaths in when
Transformer breaths in when
Which of the following property is not necessarily desirable in the material for transformer core?
Which of the following property is not necessarily desirable in the material for transformer core?
Which winding in a transformer has more number of turns?
Which winding in a transformer has more number of turns?
The transformer ratings are usually expressed in terms of
The transformer ratings are usually expressed in terms of
The efficiency of a transformer will be maximum when
The efficiency of a transformer will be maximum when
Which of the following protection is normally not provided on small distribution transformers?
Which of the following protection is normally not provided on small distribution transformers?
The voltage transformation ratio of a transformer is equal to the ratio of
The voltage transformation ratio of a transformer is equal to the ratio of
Which of the following insulating materials can withstand the highest temperature safely?
Which of the following insulating materials can withstand the highest temperature safely?
A no-load test is performed on a transformer to determine
A no-load test is performed on a transformer to determine
Which of the following properties is not necessarily desirable for the material for transformer core?
Which of the following properties is not necessarily desirable for the material for transformer core?
Insertion of resistance in the rotcir of an induction motor to develop a given torque
Insertion of resistance in the rotcir of an induction motor to develop a given torque
When secondary of a current transformer is open-circuited its iron core will be
When secondary of a current transformer is open-circuited its iron core will be
The 'cogging' of an induction motor can be avoided by
The 'cogging' of an induction motor can be avoided by
Which of the following is the most likely source of harmonics in a transformer?
Which of the following is the most likely source of harmonics in a transformer?
Harmonics in transformer result in
Harmonics in transformer result in
Distribution transformers are generally designed for maximum efficiency around
Distribution transformers are generally designed for maximum efficiency around
In case of 3-phase induction motors, plugging means
In case of 3-phase induction motors, plugging means
Efficiency of a power transformer is of the order of
Efficiency of a power transformer is of the order of
The main reason for generation of harmonics in a transformer could be
The main reason for generation of harmonics in a transformer could be
Natural air cooling is generally restricted for transformers up to
Natural air cooling is generally restricted for transformers up to
The maximum load that a power transformer can carry is limited by its
The maximum load that a power transformer can carry is limited by its
In a transformer the energy is conveyed from primary to secondary
In a transformer the energy is conveyed from primary to secondary
An open-circuit test on a transformer is conducted primarily to measure
An open-circuit test on a transformer is conducted primarily to measure
Spacers are provided between adjacent coils
Spacers are provided between adjacent coils
Which winding of the transformer has less cross-sectional area?
Which winding of the transformer has less cross-sectional area?
Material used for construction of transformer core is usually
Material used for construction of transformer core is usually
The leakage flux in a transformer depends upon
The leakage flux in a transformer depends upon
What will happen if the transformers working in parallel are not connected with regard to polarity?
What will happen if the transformers working in parallel are not connected with regard to polarity?
Which of the following is not a part of transformer installation?
Which of the following is not a part of transformer installation?
Reduction in core losses and increase in permeability are obtained with transformer employing
Reduction in core losses and increase in permeability are obtained with transformer employing
In Ns is the synchronous speed and s the slip, then actual running speed of an induction motor will be
In Ns is the synchronous speed and s the slip, then actual running speed of an induction motor will be
Which of the following parts of a transformer is visible from outside?
Which of the following parts of a transformer is visible from outside?
In a power or distribution transformer about 10 per cent end turns are heavily insulated
In a power or distribution transformer about 10 per cent end turns are heavily insulated
A common method of cooling a power transformer is
A common method of cooling a power transformer is
Iron loss of a transformer can be measured by
Iron loss of a transformer can be measured by
