Welding

1. Welding metallurgy is the study of metallurgy pertaining to? A.Welding processes B.Welding techniques C.Both A & B D.None of these Ans: C 2.A projection weld is a type of? A.Resistance weld B.Arc weld Ans: A

C.Gas weld

D.Fillet weld

3.Armoured tanks are made of? A.Armoured steel B.Mild steel Ans: A

C.Tor steel

D.Carbon steel

4.Armour steel is having tensile strength around? A.50 to 60 kg/mm square B.60 to 70 kg/mm square C.70 to 80 kg/mm square D.80 to 90 kg/mm square Ans: C 5.The procedure for welding steel castins are conformed to? A.ISI 1030-1962 B.ISI 1030-1961 C.ISI 1762-1961 Ans: A

D.None of these

6.Which effect become more pronounced with increasing frequency? A.Skin effect B.Proximity effect C.Current effect Ans: C 7. Welding metallurgy is concerned with? A.Melting of electrode B.Base metal

C.Slag metal

D.Frequency effect

D.All above

Ans: D

8.These weld symbols have no arrow-side or other-side significance? A.Projection or seam weld B.Back or backing weld C.Surface or groove weld weld Ans: D

D.Flash

9. Welding mellurgy is concerned with? A.Gas metal reaction B.Surface phenomena C.Solid state reactions D.All above 10.A back or backing weld is a type of? A.Groove weld B.Resistance weld Ans: C

C.Arc and gas weld

13.The recrystallised weld metal has? A.Maximum ductility B.Crack resistance Ans: C

D.Upset weld

D.Lap joint

C.Both A & B

these

Ans: B

D.Isometric

B.On the service conditions intended

16.Which of the following is one of the basic types of welded joints? A.T-joint B.Rear joint C.Angle joint Ans: A 17.The changes takes place in Heat affected zone due to? A.Heat B.Pressure C.Weather Ans: A

of

D. None of these

14.Welding drawings are a special type of this kind of drawing? A.Symbol B.Perspective C.Assembly 15.Weldability depends? A.Upon the process intended Ans: C

upset

Ans: D

11. The electrodes which have a coating of oxides of iron and manganese and silicates are called? A.Basic electrodes B.Acidic electrodes C.Chemical electrodes D.None Ans: B 12.This symbol indicates a surface to be built up? A.Groove weld B.Surface weld C.Corner joint

and

C.Both A & B

Ans: C D.

D.Groove joint

D.None of these

18.The corrosion resistance of welded joints influenced by? A.Chemical coposition of weld metal B.Chemical composition of parent metal

None

of

these

C.welding process employed

D.All above

Ans: D

19.Corrosion resistance of welded joints is effected due to? A.Parent metal thickness B.Number of passes Ans: E

C.Arc current

20.The strongest constituent of steel is? A.Ferrite B.Peralite Ans: B

C.Cementite

D.Austenite

21.The tensile strength of Peralite is? A.18 tons per square inch C.65 tons per square inch Ans: B

B.56 tons per square inch D.None of these

22.Specification for 1.5% manganese steel castins has been explained in? A.ISI 2708-1964 B.ISI 1030-1962 C.ISI 1762-1961 Ans: A

D.Speed of weld

D.None of these

23.High frequency current in metal conductors tends to flow at the surface of the metal. This is called? A.Skin effect B.Proximity effect C.Current effect D.Frequency effect Ans: A 24.Electric Arc was first developed in the year? A.1801 B.1810 C.1081 D.1800

Ans: A

25.Minimum voltage of direct current for establishing an arc is: A.400 volts B.40 volts C.14 volts D.4 volts Ans: B 26.The temperature of electric arc is about? A.3000 deg Celsius B.300 deg Celsius Ans: C 27.S.W.G. stands for? A.Suitable wire gauge

C.3500 deg Celsius

B.Selected wire gauge C.Special wire gauge

D.350 deg Celsius

D.Standard wire gauge Ans: D

28.In case of medium coated electrodes, the ratio of coating diameter to the core wire diameter is from? A.1.2 to 1.3 B.1.3 to 1.4 C.1.4 to 1.5 D.1.5.to 1.6 Ans: C 29.Injector type blow pipe is of? A.Low pressure type B.High pressure type Ans: A

C.Medium pressure type

30.Central white cone is found in? A.Carborising flame B.Oxidising flame Ans: C

C.Natural flame

D.None of these

D.None of these

31.Which is destructive metal test? A.Flame test B.Magnet test

C.Colour test

D.Chisel test

Ans: A

32.Kindling temperature is about? A.1250 deg Celsius B.1500 deg Celsius

C.1350 deg Celsius

D.1400 deg Celsius

Ans: C

33.The required voltage for 100 to 120mm thick steel plate inspected by X-rays radiography is? A.220 K.V. B.400 K.V. c.1000 K.V. D.150 K.V. 34.The marking of a spot weld is affected by? A.The surface condition of the material to be welded. C.The size of welding current. E.The shape and area of the electrode tip Ans: B

Ans: B

B.The electrode pressure. D.The time of application of the current. F.All above

35.D.C. welding equipment used for under water welding has a capacity of? A.50 Amps B.100 Amps C.200 Amps D.300 Amps

Ans: D

36. Purified air becomes in liquid state at: A. - 100 degree Celsius B. - 180 degree Celsius C. - 182 degree Celsius D. - 82 degree Celsius Ans: C 37.Calcium carbide is produced by fusing coke with? A.Water B.Acid C.Lime D.None of these Ans: C 38.Generally, the electrodes are produced in the length of? A.250mm B.300mm C.350mm D.450mm 39.The rough welds are due to? A.Too low current B.Too high current Ans: D 40.The metals can be identified by? A.Colour test B.Weight test C.Flame test

E.All above

Ans: E

C.Wrong arrangement of electrodes

D.All

D.Magnet test E.All above

above

Ans: E

Mark following statements as True or False: 41.Polarity of anode is positive

Ans: True

42.Wave length of gamma rays is more than that of X-rays. Ans: False 43.High pressure torches are always of non-injector type.

Ans: True

44.Melting point of pure aluminium is less than that of oxide of aluminium. Ans: False 45.4mm = 8 S.W.G. Ans: True Fill in the blanks: 46.A low hydrogen electrodes is called ....................... electrode.

Ans: Basic

47.Carbon monoxide gas is very low in ......................... welding.

Ans: Arc

48.Laser stands for ............................................ Ans: LIght Amplification by Simulated emission of Radiation 49.The core wore is of mild steel or .......................

Ans: Low carbon steel

50.Temperature of oxy-acetylene flame is ......................... than that of oxy-hydrogen

Ans: Higher

51.According to ISI (815-1956), code number consists of M followed by six digit. In this what does second digit stand for? A.Type of covering B.Welding position C.Welding curretn conditions D.Minimum tensile strength of weld metal Ans: B 52.DC electrode positive and on AC with open circuit voltage over 95 volts is indicated by? A.D+ means B.D+ A95 means C.D- A95 means D.D+ A70 means Ans: B 53. 10 SWG is equial to? Ans: C

A.10mm

54.Which one is best to increase the safety? A.MOtor-generator B.Rectifier C.Transformer

B.1mm

D.32mm

D.None of above

55.In case of welding in flat position, weld slope does not exceed? A.50 degree B.40 degree C.20 degree 56.The position in which it is easiest to weld is?

C.3.2mm

D.10 degree

Ans: A

Ans: D

A.Flat

B.Horizontal

C.Vertical

57.Zinc fumes are produced by welding of? A.Galvanised iron B.Cast iron Ans: D

D.None of these

C.Wrought iron

Ans: A

D.None of these

58.Infra red rays have a wave length raning from? A.700 to 2000 millimicrons B.725 to 2500 millimicrons C.725 to 3000 millimicrons D.750 to 2000 millimicrons Ans: D 59.Hight pressure blow pipes is of? A.Non-injector mixer pattern B.Injector mixer pattern

C.None of above

60.Under water welding is generally restricted to? A.Mild steel B.Tor steel C.High carbon steel

Ans: A

D.None of these

Ans: A

61.Commutator is used? A.To collect current from armature B.To rectify the armature AC into DC C.For both pruposes A & B D.None of these Ans: C 62.An excess quantity of oxygen is mixed with acetylene for burning and obtaining? A.Natural flame B.Oxidising flame C.Carbruising flame D.None of above Ans: B 63.When an electric arc is struck, the electrical energy available for heat energy, is about? A.30% B.40% C.50% D.60% 64.Oxygen hoses are made to stand upto? A.3 atmosphere B.10 atmosphere Ans: B

C.7 atmosphere

Ans: C

D.5 atmosphere

65.The current in the welding arc may vary from? A.10 to 20 amperes B.100 to 200 amperes C.100 to 1000 amperes D.100 to 2000 amperes Ans: D 66.The normal changing pressure of dissolved acetylene is? A.5 atmospheric pressure B.10 atmospheric pressure C.15 atmospheric pressure D.20 atmospheric pressure Ans: C 67.The recrystallised weld metal has? A.Maximum ductility B.Crack resistance

C.Both A & B

D.None of these

Ans: C

68.Explosion welding can be used for? A.Beryllium B.Tungsten

C.Boron

D.None of these

Ans: D

69.DC welding equipment used for under water welding has a capacity of? A.50 Amps B.100 Amps C.200 Amps D.300 Amps 70.Liquid oxygen is converted back to gas by using? A.Gasificator B.Generator C.Regulator

D.Valves

Ans: D

Ans: A