ITI Instructor Electrician- Previous Questions

#1. Hard magnetic materials are used for…?

in electric traction

for making permanent magnet

for making temporary magnet

for relays

#2. When phase sequence of supply at 3 phase balanced load is reversed..:

phase currents are changed

phase powers are changed

phase currents are changes in angle but not in magnitude

load power consumed is changed

#3. A frequency of 950 Hz is called…:

audio frequency

radio frequency

high frequency

ultra high frequency

#4. An electric iron is rated as 230 V , 500 W, 50 Hz. The value of 230 V refers…:

RMS Value

Peal Value

Average Value

Peak to peak value

#5. The ratio of RMS value to Average value of an alternating voltage is known as…;

form factor

peak actor

Q factor

average value

#6. The three resistance each of value 3 ohm are connected in delta. their value in each branch of equivalent star connection will be..:

9 ohm

6 ohm

3 ohm

1 ohm

#7. Which of the following gives monochromatic light..;

tube light

sodium vapour lamp

GLS lamp

mercury vapour lamp

#8. Sodium vapour lamp is best suited for…?

reading rooms

street lights

auditorium

cinema projectors

#9. The colour of light depends on…?

wave length

frequency

wave length & frequency

wave length, frequency & speed

#10. In induction motor greater the number of poles..:

lesser the speed

greater the speed

lesser the frequency

greater the frequency

#11. In induction generator operation, the slip is always…:

positive

negative

zero

infinite

#12. If any to phases of an induction motor are inter changed…:

motor will burn

motor will stop

motor will run in reverse direction

motor will continue to run in the same direction

#13. In a transformer the resistance between its primary and secondary windings is…:

zero

very small

cannot be predicted

infinite

#14. Iron loss for transformer is 400 Watts, what will be the copper loss when the transformer is working on its maximum efficiency?

400 Watts

1600 Watts

200 Watts

100 Watts

#15. Which of the following conditions is not necessary for the parallel operation of two transformers?

percentage impedence should be the same

polarities of both secondaries should be the same

voltage ratings should be the same

KVA ratings should be same

#16. The phase shift in a star star connected 3 phase transformer is…:

0

30

60

120

#17. Which test on a transformer provides information about regulation, efficiency and heating under load conditions?

open circuit test

short circuit test

back to back test

hopkinson's test

#18. Material used for making transformer core is…:

cast iron

cast steel

high silicon steel

high carbon steel

#19. An auto transformer has …… winding..:

one

two

three

four

#20. Iron loss in transformer occurs in…:

core

winding

insulating oil

main tank

#21. In a cable the voltage stress is maximum at…:

insulator

sheath

surface of conductor

core of the conductor

#22. The resistance of a straight conductor does not depends upon its…:

temperature

material

length

shape of cross section

#23. The method of heating used in an electric room heater is…:

resistance heating

induction heating

dielectric heating

arc heating

#24. Dielectric material is a ….:

resistor

insulator

conductor

capacitor

#25. Western cadmium cell is a…:

primary cell

secondary cell

dry cell

rechargeable cell

ITI Instructor Electrician- Previous Questions

#1. Hard magnetic materials are used for…?