4th Class Power Engineering Unit A8 Chapter 5: Transformers Exam UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

4th Class Power Engineering Unit A8
Chapter 5: Transformers Exam UPDATED
ACTUAL QUESTIONS AND CORRECT
ANSWERS
Current transformers step down the current rather than the:

Select one:

a. resistance

b. voltage

c. conductance

d. number of poles - CORRECT ANSWER b



Three major losses which occur in a transformer are iron losses, copper losses and:

Select one:

a. cooling losses

b. heat losses

c. flux leakage

d. capacitive losses - CORRECT ANSWER c



Dry type transformers that are not fan cooled are called:

Select one:

a. capacitive transformers

b. low capacitive transformers

c. ventilated transformers

d. non-ventilated transformers - CORRECT ANSWER d



What are the microscopic magnetic particles called:

Select one:

a. hysteresis

, b. eddy currents

c. conductor reluctance

d. domains - CORRECT ANSWER d



A transformer has a primary voltage of 440 volts and 20 turns on the primary winding. If the
secondary winding has 10 turns the voltage of the secondary is:

Select one:

a. 220 volts

b. 200 volts

c. 880 volts

d. 22 volts - CORRECT ANSWER a



The difference between three phase and single phase transformers is that:

Select one:

a. primary and secondary windings are wound on each of the three legs in 3 phase

b. Three individual coils in three phase

c. cannot be used as set down transformers

d. cannot be shell-type transformers - CORRECT ANSWER a



A transformer has a primary voltage of 500 volts and 20 turns on the primary winding. If the
secondary winding has 5 turns the voltage of the secondary is:

Select one:

a. 2000 volts

b. 2500 volts

c. 125 volts

d. 100 volts - CORRECT ANSWER c



Iron losses in transformers are caused by:

Select one:

a. hysteresis

b. eddy currents