2016 FEBRUARY WIREMAN THEORY SEMESTER-IV

2016 FEBRUARY WIREMAN THEORY SEMESTER-IV

1. In a power transformer the current flowing in
the coil connected to the AC source is..........

A   LT winding

B   primary winding

C   HT winding

D   secondary winding _

Answer:- B   primary winding

2. The transformer used to transmit the power
to longer distance is called as..............

A   current transformer

B  step up transformer

C  voltage transformer

D  step down transformer

Answer:- B  step up transformer

3. The function of this magnetizing current (1m)

is to.......

A  magnetize the core
B  energize the primary winding
C   energize the secondary winding
D  to the compensate the loss

Answer:- A  magnetize the core

4. The magnetizing current (lm) is very small in
magnitude and lags the applied voltage (Vs)

by.........

A 120°

B 90°

C 60°

D 30°

Answer:- B 90°

5. The RMS value of emf induced in the
primary winding (Ep) of a transformer is

A   4.40 𝛟MN volt

B 4.44<|>𝛟JNvolt
C   4.44𝛟fN volts
D 4.44𝛟𝑚𝒎<j»mfvolt

Answer:- B 4.44<|>𝛟JNvolt

6. The transformation ratio (K) is more than 1

then the transformer is a........

A  step up transformer
B  auto transformer
C  step down transformer
D   current transformer

Answer:- A  step up transformer

7. In which condition the maximum efficiency

will occur in transformer?
A   iron loss greater than copper loss
B   iron loss equal to copper loss
C  copper loss greater than iron loss
D  copper loss less than eddy current loss

Answer:- B   iron loss equal to copper loss

8. To ensure that the core insulation between
clamp plates and core bolts is adequate, the
test voltage applied is.........

A  1.0 KV

B   1.5 KV

C  2.0 KV

D   2.5 KV

Answer:- C  2.0 KV

9. As per IE rule, in H - type pole mounted
sub -station, minimum clearance between
live conductor and earth structure is..........

A  305 mm

B  310 mm

C   315 mm

D   320 mm

Answer:- A  305 mm

10. The incoming and outgoing lines in a sub -
station are connected to...............

A ACB

B OCB

C  bus bar

D  gang isolator

Answer:- C  bus bar

11. Bus bar assembly should be installed at a

height from the ground is........

A 2.75 m
B 2.50 m
C 2.25 m
D  2.15 m

Answer:- A 2.75 m

12. The bus bar sections are available in

standard length of............

A 3.50 m
B 3.55 m
C 3.60 m
D  3.65 m

Answer:- D  3.65 m

13. For bolts and nuts used for connecting
aluminium bus bar shall be........

A   tinned forged brass

B iron

C copper

D steel

Answer:- A   tinned forged brass

14. Bus bar supports are spaced (maximum)

apart is..........

A 500 mm
B 550 mm
C 600 mm
D  650 mm

Answer:- C 600 mm

15. The temperature of cooker is controlled

by........

A thermostat switch

B  SPT switch

C  two way switch

D  push button switch

Answer:- A thermostat switch

16. Rod type thermostats are being used in
A  geysers cooking ranges
B small mixers
C  room heater
D  cooling ovens

Answer:- A  geysers cooking ranges

17. The name of mercury switch used in a power

transformer is.........

A  current relay
B  buchholz's relay
C  voltage relay
D  thermal relay

Answer:- B  buchholz's relay

18. In the distribution substation the step down
voltage 3 phase, 4 wire for supply is........

A 440V

B 415V

C   410 V

D   400 V

Answer:- D   400 V

19. The lightning arresters to protect the
substation from lighting is installed on

A   HT side

B  primary side

C  LT side

D   secondary side

Answer:- A   HT side

20. The pole mounted sub stations are generally
used for transformer capacity upto.........

A  250 KVA

B   200 KVA

C   150 KVA

D 110KVA

Answer:- B   200 KVA

21. The OCB is installed on the
A  HT side
B  LT side
C  primary side
D   secondary side

Answer:- B  LT side

22. As per IE rules to H - type pole mounted
sub stations, phase to phase clearance
between jumpers is..............

A  0.91 m

B  0.90 m

C   0.81 m

D   0.80 m

Answer:- A  0.91 m

23. Pellet type lead oxide arrestor acts as an
insulator if the temperatures increased
beyond.............

A 130°C

B 140°C

C 145°C

D 150°C

Answer:- D 150°C

24. ACB stands for..........

A  Air Circuit Breaker
B   Air Current Breaker
C   Air Case Breaker
D   Air Conductor Breaker

Answer:- A  Air Circuit Breaker

25. Transformers used to transform high voltage

and high current is...............

A  two coil transformer
B   current transformer
C  potential transformer
D  instrument transformer

Answer:- D  instrument transformer

26. Which one is the specification of potential

transformer?
A  Voltage ratio
B Current
C Wattage
D Impedance

Answer:- A  Voltage ratio

27. EHT stands for............

A  Extra High Terminal
B   Extra High Tension
C   Extra High Thermostat
D  Equipment High Tension

Answer:- B   Extra High Tension

28. Underground L.T cables voltage capacity

is...........

A 1.1 KV and below
B 2.2 KV and below
C 3.0 KV and below
D   3.3 KV and below

Answer:- A 1.1 KV and below

29. Full form of Mi cables is ……
A  Multi Insulated cables
B  Mineral Insulated cables
C  Multi Insulated conductor
D  Mini Insulated cables

Answer:- B  Mineral Insulated cables

30. In UG cable joints, the cold pouring
compound consists of a resin base and a
hardener which is.........

A  poly amino

B  poly vinyl

C   poly chloride

D  poiy methyl

Answer:- A  poly amino

31. The mixture of the compound used in UG
cable joints is resin and hardener, this is
churned till the compound colour is..........

A blue

B grey

C white

D red

Answer:- B grey

32. The bituminous compound melting

temperature is.........

A 100°C
B 90°C
C 80°C
D 70°C

Answer:- B 90°C

33. The electrolyte used in simple voltaic cell

is...............

A   dilute sulphuric acid
B  ammonium chloride
C  potassium hydroxide
D  zinc oxide

Answer:- A   dilute sulphuric acid

34. The potential difference in volts is

A   emf-IaRa

B   emf-IR

C   emf-P.D

D   PD - emf

Answer:- A   emf-IaRa

35. High energy density battery used in

spacecraft is..........

A  lead acid battery

B  lithium battery

C  nickel cadmium cells/battery

D  alkaline manganese cells/battery

Answer:- B  lithium battery

36. The capacity of the cell/battery is expressed

in..........

A  Ah
B  Wh
C  Wsec
D  A sec

Answer:- A  Ah

37. A 20 Ah battery can supply 1A current

for.........

A  0.02 hr
B  0.2 hr
C  2.0 hr
D  20 hr

Answer:- D  20 hr

38. The Leclanche cell contains a strong solution

of.................

A  ammonium chloride
B  potassium hydroxide
C  manganese dioxide
D  sulphuric acid

Answer:- A  ammonium chloride

39. Local action in a simple voltaic cell, are seen

from the...........

A  positive plate
B zinc plate
C  carbon plate

D  lead plate

Answer:- B zinc plate

40. The plante plates in a lead acid battery are

made of...........

A  pure lead
B  lead peroxide
C  lead sulphate
D  nickel hydrate

Answer:- A  pure lead

41. The specific gravity of an electrolyte is

measured with a ……
A pyrometer
B hydrometer
C thermometer
D galvanometer

Answer:- B hydrometer

42. Which one of the following will ascertain the
condition of the lead acid battery?

A specific gravity

B  no of plates

C  area of plates

D  distance between plates

Answer:- A specific gravity

43. In a fully charged lead acid battery the

specific gravity is.............

A 1.26
B 1.20
C 1.18
D 1.15

Answer:- A 1.26

44. A secondary battery should not be
discharged beyond the minimum value of
voltage is...........

A   1.3 V

B 1.5V

C   1.7 V

D   1.8 V

Answer:- C   1.7 V

45. Secondary cell temperature during charge
does not exceed the limit specified............

A 40°C

B  41 °C

C 42°C

D 43°C

Answer:- D 43°C

46. In larger transformers a stepped core
arrangement is used to minimize the use of
copper and............

A  iron loss

B  eddy current loss

C  hysteresis loss

D  copper loss

Answer:- D  copper loss

47. Transformer lamination thickness for 50 HZ

is.............

A 0.25 mm
B 0.24 mm
C 0.23 mm
D  0.22 mm

Answer:- A 0.25 mm

48. Primary winding has 450 turns and
secondary winding has 90 turns. What wilt be
the secondary voltage if primary voltage is
220 volt?

A   45 volt

B   44 volt

C   42 volt

D   40 volt

Answer:- B   44 volt

49. The secondary impedance of a transformer

is............

Answer:-A