Transformers MCQ ,Questions and Answers Part-1

 Transformer Numerical Questions and Answers.

Transformers MCQ

Transformers Multiple Choice Questions and Answers MCQs Electrical and Electronics Engineering  Transformers, Current transformer; Voltage transformer. Power transformer,

 

1. A Buchholz relay can be installed on

A) Auto-transformers
B) Air-cooled transformers
C) Welding transformers
D) Oil cooled transformers

ANSWER= (D) Oil cooled transformers

 

2. The chemical used in breather is

A) Asbestos fiber
B) Silica sand
C) Sodium chloride
D) Silica gel

ANSWER= (D) Silica gel

 

3. Material used for construction of transformer core is usually

A) 0.4mm to 0.5 mm
B) 4mm to 5 mm
C) 14mm to 15 mm
D) 25mm to 40 mm

ANSWER= (D) 25mm to 40 mm

 

4. Helical coils can be used on 

A) Low voltage side of high kVA transformers
B) High-frequency transformers
C) High voltage side of small capacity transformers
D) High voltage side of high kVA rating transformers

ANSWER= (A) Low voltage side of high kVA transformers

 

5. The transformer ratings are usually expressed in terms of

A) Volts
B) Amperes
C) kW
D) kVA

ANSWER= (D) kVA

 

6. The value of flux involved in the emf equation of a transformer is

A) RMS value
B) RMS values
C) Maximum value
D) Instantaneous value

ANSWER= (C)Maximum value

 

7. The main advantage of an autotransformer over a two winding transformer is

A) Hysteresis losses are reduced
B) Saving in winding material
C) Copper losses are negligible
D) Eddy losses are totally eliminated

ANSWER= (B)Saving in winding material

 

8. During short circuit test iron losses are negligible because

A) The current on the secondary side is negligible
B) The voltage on the secondary side does not vary
C) The voltage applied on the primary side is low
D) Full-load current is not supplied to the transformer

ANSWER= (C) The voltage applied on the primary side is low

 

9. Which of the following properties is not necessarily desirable in the material for transformer core?

A) Mechanical strength
B) Low hysteresis loss
C) High thermal conductivity
D) High permeability

ANSWER= (C) High thermal conductivity

 

10. The main reason for the generation of harmonics in a transformer could be

A) Fluctuating load
B) Poor insulation
C) Mechanical vibrations
D) Saturation of core

ANSWER= (D) Saturation of core

 

11. A transformer transforms

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

ANSWER= (D) voltage and current

 

12. Which is not the basic element of the transformer?

A) core
B)  primary winding
C) secondary winding
D) mutual flux

ANSWER= (D) mutual flux

 

13. In an ideal transformer.

A) Windings have no resistance
B) core has no losses
C) core has infinite permeability
D) All of the above

ANSWER= (B) All of the above

 

14. The frequency of the secondary voltage of a transformer will be...

A) Less than the frequency of the primary voltage
B) Equal to the primary voltage
C) Greater than the frequency of the primary voltage
D) Much greater than the frequency of the primary voltage

ANSWER= (B) Equal to the primary voltage

 

15.The efficiency of a transformer is maximum when

A) It runs at half full load
B) it runs at full load
C) its Cu loss equal iron loss
D) it runs overload

ANSWER= (C) its Cu loss equal iron loss