2016 FEBRUARY ELECTRICIAN THEORY SEMESTER – 2

2016 FEBRUARY  ELECTRICIAN THEORY SEMESTER – 2

1.Which part of the CRO, controls the

sharpness of the trace?
A   Power - ON
B   Intensity
C   CAL switch
D   Trigger level

ANSWER:- B   Intensity

2. What is the peak to peak voltage of 240 V
r.m.s main AC voltage in CRO?

A   339 volt

B   268 volt

C   252 volt

D   240 volt

ANSWER:- A   339 volt

3. Which one is the application of low power

transistor?
A  Loud speaker
B   TV receiver
C   Second stage amplifier
D Microphone

ANSWER:- D Microphone

4. The barrier potential of silicon semiconductor

used in transistor is..............

A   0.3 volt
B   0.5 volt
C   07 volt
D   0 8 volt

ANSWER:- C   07 volt

6. Which type of oscillators are is used in signal

generator?
A   Crystal oscillator
B   Colpit's oscillator
C   Hartley oscillator
D   Relaxation oscillator

ANSWER:- B   Colpit's oscillator

7. IGBT stands for...........

A   integrated Gate Bi-directional Transistor
B  Integrated Gate Bipolar Transistor
C   Integrated Gate Blocky Transistor
D   Insulated Gate Bipolar Transistor

ANSWER:-  D   Insulated Gate Bipolar Transistor

8. What is the correct decimal number of the

binary digit of '0100'?

A)  1   B) 2  C)  3  D)  4

ANSWER:-  D)  4

9. The wall thickness of heavy gauge 20mm

size of conduit is..........

A 1.0 mm
B 1.2 mm
C 1.8 mm
D  2.0 mm

ANSWER:- C 1.8 mm

10. PVC channel wiring is suitable for.,
A. go - down wiring
B  industrial wiring
C  out - door wiring
D  indoor surface wiring

ANSWER:- D  indoor surface wiring

11. The conduit elbows are used at
A  tapping the connection
B  sharp ends
C  straight runs
D   away from walls

ANSWER:- B  sharp ends

12.depth of junction boxes used

in roof slabs shall be........

A 75 mm
B 70 mm
C 65 mm
D   60 mm

ANSWER:- C 65 mm

13. Name the type of switch shown in the symbol
 below figure?

A  Two way switch
B  Toggle switch
C  Bell push switch
D  Intermediate switch

ANSWER:- D  Intermediate switch

14.Which type of relays hold their contacts in
position even after power is cut off?

A  Under current relay

B  Voltage sensing relay

C  Latching relay

D   Current sensing relay

ANSWER:- C  Latching relay

15. The fusing factor of HRC fuse
A 2.0
B 1.7
C 1.4
D 1.1

ANSWER:- D 1.1

16.In Fleming's right hand rule, the fore finger

indicates............

A  the direction of magnetic flux

B  the direction of induced e.m.f

C  the direction of motion of the conductor

D  the direction of induced current

ANSWER:- A  the direction of magnetic flux

17.The function of brushes in the DC

generators............

A  convert AC into uni - directional current
B  collect the current from the commutator
C  increase the magnetic flux
D  connect the armature and commutator

ANSWER:- B  collect the current from the commutator

19. How many parallel paths in 6 pole, simplex
lap wound armature in DC generator is.......

A. 4

B  6

C  8

D 12

ANSWER:- B  6

20.The cross • magnetizing effect of armature
reaction in DC generator can be nullified

By ……………..
A  inserting compensating winding

B  providing inter poles between the main pole

C   shifting the brush position from GNA to MNA

D  increasing the ampere - turns in the field

winding

ANSWER:- C   shifting the brush position from GNA to MNA

21.The one of the application of under
compounded DC generator is..........

A  for electro plating

B   for welding generator

C   for street lights

D   for railways

ANSWER:- A  for electro plating

22. Which rule is applied to identify the direction
of motion of the conductor in DC motor?

A   Flemings right hand rule

B   Flemings left hand rule

C   Cork's screw rule

D   Right hand thumb rule

ANSWER:- B   Flemings left hand rule

24. Which type of DC motor is used in hoists and

cranes?
A   DC series motor
B   DC shunt motor
C   DC cumulative compound motor
D   DC differential compound motor

ANSWER:- A   DC series motor

25.Which method of speed control is mainly

applied in electric trains?
A   Series field tapping method
B   Series field diverter method
C  Series parallel method
D  Supply voltage control method

ANSWER:- B   Series field diverter method

26.What is the cause for the DC motor's brush
makes chattering or hissing noise during
operation?

A Over loading

B Insufficient brush tension

C Short circuit in commutator segment

D incorrect brush spring pressure

ANSWER:- D incorrect brush spring pressure

                                                                                      

27. A long shunt compound generator delivers a
load current of 100A at 400V, the shunt field
resistance is 200 ohm. Calculate the
armature current?

A 100A

B 102A

C 4A

D 2A

ANSWER:- B 102A

28.Which one is the main condition for
paralleling of DC generators?
A   The capacity of both generators must be
same

B   The field critical resistances must be same
C  The polarities of both generators must be
same

D  The maximum efficiency of both generator
must be same

ANSWER:- C  The polarities of both generators must be
same

29.Which one of the following is the reason for
loosing the residual magnetism of self
excited DC generator?
A   The armature core is not properly laminated
B   The generator is kept idle for a long time
C   The armature resistance is more than 1 ohm
D   Incorrect brush position

ANSWER:- B   The generator is kept idle for a long time

30.Which one of the following is the application
of over compounded DC generator?

A Electroplating

B Railways

C   Welding generator

D Lathes

ANSWER:- B Railways

32.The input side of the single phase
transformer is called as..........

A  secondary side

B   primarily side

C  high voltage side

D   low voltage side

ANSWER:- B   primarily side

33.In which material core of the transformer is

constructed?

A  Silicon iron steel

B  Mild steel iron

C   Carbon steel iron
D   Pig iron steel

ANSWER:- A  Silicon iron steel

35.If the full load iron loss of the transformer is
1000watt, what will be the iron loss at half
load?

A  125 watt

B   250 watt

C   500 watt

D   1000 watt

ANSWER:- D   1000 watt

37.A 100 KVA, 2400V/240V, 50HZ transformer
has 300 turns on the secondary winding
calculate the number of turn in primary
winding?

A   1500 turns

B   1800 turns

C   2400 turns

D   3000 turns

ANSWER:- D   3000 turns

38.The standard values of rated secondary
current of the current transformer is.......

A   2 Amp

B   3 Amp

C   5 Amp

D   10 Amp

ANSWER:- C   5 Amp

39.What will be the colour of the silicon gel,
after it absorbs moisture from air?

A Blue

B Brown

C Violet

D Pink

ANSWER:- A Blue

40.One of the application of AC to DC drive

control is............

A robotics
B compressors
C   servo application
D  electric traction

ANSWER:- D  electric traction

41.In measuring instruments, the reading
accuracy of measuring device must always

be..................

A  lower than the measuring accuracy
B  greater than the measuring accuracy
C  the same as measuring accuracy
D   the specified range of measuring accuracy

ANSWER:- B  greater than the measuring accuracy

42.Which type of scale is used primarily in
moving coil measuring device?

A   Non - linear scale

B   Extended scale

C   Linear scale

D   Fine scale

ANSWER:- C   Linear scale

43.Which type of instrument belongs to the

integrating instrument type?
A   Energy meter
B   Voltmeter
C   Ammeter

D   Electro cardio graph (ECG)

ANSWER:- A   Energy meter

44.If the pointer moves quickly to its final
deflected position without any sort of
oscillation, that damping is called as..

A   under damping

B   over damping

C   critical damping

D   air friction damping

ANSWER:- C   critical damping

45.The creeping error in energy meter can be

arrested by.............

A   replacing the rotating disc with new one

B  drilling two diametrically opposite holes in the

disc

C   reducing the considerable load
D   increasing the gap between the disc and
permanent magnet

ANSWER:- B  drilling two diametrically opposite holes in the

disc

46.Which is the main precaution to be taken

before taking any measurement by using

tong tester?
A  Set-the tester in correct range
B  Make looping the conductor more than once

through the core
C   Make sure the indication is at zero on the

scale

D  Read the indicator position on the scale

ANSWER:- C   Make sure the indication is at zero on the

scale

47.For measuring the current, voltage (or)
.resistance by multimeter, which control
switch to be set?
A  Range switch
B  Selector switch
C  Power ON - OFF switch
D  Function switch

ANSWER:- D  Function switch

48.How many segments are in both LCD and
LED, Digital Mufti Meter (DMM) display?

A 9

B 8

C 7

D 6

ANSWER:- C 7

49.In 3 element 3 phase energy meter, how

many number of aluminium discs are

mounted?

A  1  B  2  C  3  D  4

ANSWER:- A  1 

50.When 1 milli ampere is flowing through the
meter coil is having 1000 ohms, and is
causing F.S.D, the voltage developed across
the coil resistance will be............

A   1000 volt

B   100 volt

C   10 volt

D   1 volt

ANSWER:- D   1 volt