Electrician Theory Solved Paper ||Sem-1st // Paper-1st // NCVT Exams. July 2019||

Electrician Theory Solved Paper ||Paper-1st, Sem-1st, NCVT Exams. July 2019||

1. What is 'smothering' in extinguishing of fire ?

a) Adding fuel element to the fire

b) Isolating the fire from supply of oxygen

c) Using of water to lower the temperature

d) Removing the fuel element from the fire

Ans.-(b)

2. What is the disadvantage of solid conductor compared to stranded conductor ?

a) Less rigidity

b) Less flexibility

c) Low melting point

d) Low mechanical strength

Ans.-(b)

3. Which type of joint is used in over head lines for extending the length of wire ?

a) Scarfed joint

b) Britannia 'T' joint

c) Western union joint

d) Britannia straight joint

Ans.-(c)

4. What is the name of the soldering method ?

a) Dip soldering

b) Soldering with blow lamp

c) Soldering with soldering gun

d) Temperature controlled soldering

Ans.-(d)

5. What is the cause for cold solder defect in soldering ?

a) Excessive heating

b) Insufficient heating

c) Incorrect use of solder

d) High wattage soldering iron

Ans.-(b)

6. Which formula is used to calculate the power of a DC circuit ?

a) Voltage x time

b) Current x voltage

c) Current x resistance

d) Voltage x resistance

Ans.-(b)

7. Calculate the hot resistance of 200W / 250V rated lamp.

a) 31.25 Ω

b) 62.5 Ω

c) 312.5 Ω

d) 625 Ω

Ans.-(c)

8. What happens to the voltmeter if it is connected as an ammeter? 

a) Low reading

b) No deflection

c) Meter burns out

d) Overshoot deflection

Ans.-(a)

9. What is the value of resistance in an open circuit? 

a) Zero

b) Low High

d) Infinity

Ans.-(d)

10. Which resistor the lowest current flows in a parallel circuit having the values ​​of 50Ω, 220Ω, 450Ω and 560Ω connected with supply? 

a) 50Ω

b) 220Ω

c) 450Ω

d) 560 Ω

Ans.-(d)

11. What is the specific resistance value of copper conductor? 

a) 1.72 Ohm/cm³

b) 1.72 Micro ohm

c) 1.72 Micro ohm/cm³

d) 1.72 Micro ohm/m

Ans.-(c)

12. Which is inversely proportional to the resistance of a conductor? 

a) Length

b) Resistivity

c) Temperature

d) Area of ​​cross section

Ans.-(d)

13. What is the SI unit of specific resistance? 

a) Ohm / cm

b) Ohm / m²

c) Ohm - m

d) Micro ohm / cm²

Ans.-(c)

14. Why most of semi conductor devices are made by silicon compared to germanium? 

a) High barrier voltage

b) High resistance range

c) High thermal conductivity

d) High current carrying capacity

Ans.-(a)

15. How does the depletion region behave? 

a) As resistor

b) As insulator  

c) As conductor

d) As semi conductor

Ans.-(b)

16. Wnat is the output voltage if the center tap of transformer is open circuited in a full wave rectifier circuit? 

a) Zero voltage

b) Full rated output

c) Half of the rated output

d) One fourth of rated output MCB

Ans.-(a)

17. Which is the example for coarse excess current protection? 

a) MCB

b) MCCB

c) H.R.C fuses

d) Rewireable type fuse unit

Ans.-(d)

18. Which is proportional for the deflection of ohmmeter needle in earth resistance tester?

a) Current in current coil

b) Current in potential coil

c) Speed ​​of the handle rotation

d) Ratio of the current in two coils

Ans.-(d)

19. Which principle the earth resistance tester works? 

a) Self induction

b) Mutual induction

c) fall of potential method

d) Fleming's left hand rule

Ans.-(c)

20. Why system earthing is different in utilization than equipment earthing? 

a) It protects human only

b) It protects from all circuit faults

c) It is associated with current carrying conductors

d) It is connected to the non current carrying metal work a

Ans.-(c)

21. What is the effect if a person receives a shock current of 20 MA 

a)  No sensation

b) Painful shock

c) Heart convulsions

d) Become unconscious

Ans.-(b)

22. Which electrical equipment 'L' series type MCB's are used? 

a) Geysers

b) Locomotives

c) Halogen lamps

d) Air conditioners

Ans.-(a)

23. What does the symbol marked 'X' indicated?

a) Number of wires run on the limb

b) Number of switches to be connected

c) Number of battern (or) pipe to be fixed

d) Number of clamps (or) clips to be fixed

Ans.-(a)

24. What is the name of BIS symbol used in  layout?

a) One way switch

b) Two way switch

c) Intermediate switch  

d) Multi position switch

Ans.-(d)

25. What is the name of diagram?

a) Wiring diagram

b) Circuit diagram

c) Layout diagram

d) Installation plan

Ans.-(d)

26. Which property of magnet is illustrated ?

a) Directive property

b) Induction property

c) Saturation property

d) Poles existing property

Ans.-(a)

27. Which is a paramagnetic substance ?

a) Air

b) Steel

c) Glass

d) Water

Ans.-(a)

28. Willich method of magnetization is used to make commercial purpose permanent magnets ?

a) Induction method

b) Single touch method

c) Double touch method

d) Divided touch method

Ans.-(a)

29. Wyni is the effect of inductance if the distance between the turns increases ?

a) Increases

b) Decreases

c) Becomes zero

d) Remains same

Ans.-(a)

30. What is the function of dielectric insulator in capacitor ?

a) Increases the strength of capacitance

b) Prevents any current flow between plates

c) Protects from short circuit between the plates

d) Helps to hold the charge in capacitor for long period

 Ans.-(b)

31. Which factor is determining the value of capacitance in capacitor ?

a) Area of the plates

b) Shape of the plates

c) Material of the plates

d) Thickness of the plates

 Ans.-(a)

32. Which type of capacitors are used in RF coupling circuit ?

a) Tantalum

b) Monolithic

c) Electrolytic

d) Metalized poly propylene

 Ans.-(b)

33. Which is used as a positive electrode in a dry cell ?

a) Zinc

b) Carbon

c) Copper

d) Lithium

Ans.-(b)

34. What happen to the terminal voltage of a cell if load increases ?

a) Increases

b) Decreases

c) Falls to zero

d) Remains same

 Ans.-(b)

35. How local action defect is prevented in voltaic cell ?

a) By connecting cells in series

b) By using a depolarizing agent

c) By connecting cells in parallel

d) By amalgamating the zinc plate

Ans.-(d)

36. What does the letter ‘Z’ indicate in the formula M=Z/It

a) Time in seconds

b) E.C.E of electrolyte

c) Amount of current in Amp

d) Mass deposited in grams

Ans.-(b)

37. What is the Electro Chemical Equivalent ( ECE ) of copper ?

a) 0.329 mg / coulomb

b) 0.329 mg - coulomb

c) 1182 mg / coulomb

d) 1.1182 mg – coulomb

 Ans.-(a)

38. Which is the cause for buckling defect in lead acid battery ?

a) Overcharging or over discharging

b) Charging with low rate for short period

c) Formation of sediments falling from the plate

d) Battery is kept in discharged condition for long period

Ans.-(a)

39. Which apparatus is used to check the charging condition of voltage in battery ?

a) Voltmeter

b) Multimeter

c) Hydrometer

d) High rate discharge tester

Ans.-(d)

40. Which formula is used to calculate Form factor (K_f) ?

a) K_f =Effective value/ Average value

b) K_f = Average value/Effective value

c) K_f = Effective value/Maximum value

d) K_f = Average value/Maximum value

 Ans.-(a)

41. Which formula is used to calculate the impedance ( z ) of a RLC series circuit ?

a) Z =R² + ( X_L-X_C)²

b) Z =√R² + ( X_L-X_C)

c) Z =√R + ( X_L-X_C)

d) Z =√R² + ( X_L-X_C)²

Ans.-(d)

42. What is the formula to calculate the reactive power in a 3 phase delta connected circuit ?

a) P = √3 V_L I_L sinØ

b) P = 3 V_P I_P sinØ

c) P = √3 V_L I_L CosØ

d) P = √3 V_P I_P cosØ

Ans.-(a)

43. What is the power factor if one of the wattmeter gives negative reading in two wattmeter method of 3 phase power measurement ?

a) 0

b) 0.5

c) Unity

d) Less than 0.5

Ans.-(d)

44. What is the phase displacement between phases in a 3 phase circuit ?

a) 90°

b) 120°

c) 180°

d) 360°

Ans.-(b)

45. What is the reciprocal of inductance in AC parallel circuit ?

a) Impedance

b) Admittance

c) Susceptance

d) Conductance

Ans.-(c)

46. Which condition is called as resonance RLC circuit ?

a) X_L > Xc

b) Xc > X_L

c) X_L = X_c

d) R< X_L

Ans.-(c)

47. What is the name of tool ?

a) Claw hammer

b) Tacks hammer

c) Cross pein hammer

d) Straight pein hammer

Ans.-(b)

48. Which type of chisel is used for separating metals after chain drilling ?

a) Flat chisel

b) Web chisel

c) Cross cut chisel

d) Diamond point chisel

Ans.-(b)

49. Which type of stake is used for riveting or seaming tapered cone shaped articles ?

a) Square stake

b) Hatchet stake

c) Blow horn stake

d) Bevel edged square stake

Ans.-(c)

50. Which causes knot defect in timbers ?

a) Defective storage

b) Uneven shrinkage

c) Growth of branches

d) Improper seasoning

Ans.-(c)