Nimi mock test Transformers Online Quiz Part-2

Energy conservation techniques in Transformer MCQ

Transformers EEE.

Transformers MCQ Test & Online Quiz/ We have listed below the best Transformers MCQ Questions, nimi mock test

1. A step-up transformer increases

A) voltage
B) current
C) power
D) frequency

ANSWER= (A) voltage

 

2. Which type of loss is not common to the transformer and rotating machines?

A) Eddy current loss
B) Copper loss
C) Hysteresis loss
D) Windage loss

ANSWER= (D) Windage loss

 

3. The transformer core is laminated to

A) Reduce the copper losses
B) Reduce the core losses
C) Reduce the eddy current losses
D) None of the above

ANSWER= (C) Reduce the eddy current losses

 

4. Transformer cores are built up from laminations rather than from solid metal so that

A) Oil penetrates the core more easily
B) Eddy current loss is reduced
C) Less lamination is required for the windings
D) Turn ratio is higher than voltage ratio

ANSWER= (B) Eddy current loss is reduced

 

5. The main purpose of using core in a transformer is to

A) Decrease iron losses
B) Prevent eddy current loss
C) Eliminate magnetic hysteresis
D) Decrease reluctance of the common magnetic circuit

ANSWER= (D) Decrease reluctance of the common magnetic circuit

 

6. The ordinary two winding transformer's primary and secondary windings always have

A) Different no of turns
B) Same size of copper wire
C) A common magnetic circuit
D) Separate magnetic circuits

ANSWER= (C) A common magnetic circuit

 

7. No-load test on a transformer is carried out to find

A) copper loss
B) magnetizing current
C) magnetizing current and no-load loss
D) efficiency of the transformer

ANSWER= (C) magnetizing current and no-load loss

 

8. Transformers are rated in KVA instead of KW because

A) load power factor is often not known
B) KVA is fixed whereas KW depends on the load power factor
C) Total transformer loss depends on volt-ampere
D) It has become customary

ANSWER= (C) Total transformer loss depends on volt-ampere

 

9. Transformer cores are laminated in order to

A) simplify its construction
B) minimize eddy current loss
C) reduce cost
D) reduce hysteresis loss

ANSWER= (B) minimize eddy current loss

 

10. A step up transformer increases

A) voltage
B) current
C) power
D) frequency

ANSWER= (A) voltage

 

11. In a two winding transformer, the primary and secondary induced emf E1 & E2 are always

A) equal in magnitude
B) anti-phase with each other
C) in phase with each other
D) determined by load on the transformer secondary

ANSWER= (C) in phase with each other

 

12. In a transformer, the leakage flux of each winding is proportional to the current in that winding because

A) Ohm's law applies to magnetic circuits
B) Leakage paths do no saturate
C) the two windings are electrically isolated
D) mutual flux is confined to the core

ANSWER= (D) Leakage paths do no saturate

 

13. In a two winding transformer, the emf /turn in the secondary winding is always......the induced emf power turn in primary

A) equal to k times
B) equal to 1/k times
C) equal
D) greater than

ANSWER= (C) equal

 

14. In transformer terminology, the ratio 20:1 indicates that

A) there are 20 turns on primary one turn on secondary
B) secondary voltage is 1/20th of the primary
C) primary current is 20 times greater than the secondary current
D) for every 20 turns on primary, there is one turn on secondary

ANSWER= (B) secondary voltage is 1/20th of the primary

 

15.In performing the short circuit test of a transformer

A) high voltage is usually short-circuited
B) low voltage side is usually short-circuited
C) any side is short-circuited with preference
D) none of the above

ANSWER= (B) low voltage side is usually short-circuited