BGAS Grade 2/3 Model Multiple Choice question & answers - Part 4

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 76. Which of the effect produce when rogue peaks are concentrated areas? 

a) Rash Rusting 

b) Flash Rusting 

c) Rust Staining 

d) Rust Blooming 

 




77. What is the cause of  rash rusting? 

a) Mill scale contamination 

b) Hygroscopic salts 

c) Rogue Peaks 

d) Contaminated blast abrasive 

 

78. What is the reason for spot rusting? 

a) Surface contamination 

b) Millscale 

c) Rogue peak 

d) Hygroscopic salt 

 

79. The correct ratio of a working mix would be 

a) 70-80% Grit : 20-30% Shot 

b) 50% Grit : 50% Shot 

c) 70-80% shot : 20-30% Grit 

d) 20-25% Sand : 75-80% Copper Slag 

 

80. Metallic Shot also has which affect upon the material? 

a) Stress relieves 

b) Physically deforms 

c) Work hardens

d) Causes Slivers 

 

81. What are the properties of an abrasive? 

a) Size ,Hardness,Density,shape 

b) Velocity, Impingement, Time spend, Shape 

c) Rash, Rust rashing, Rust spotting, Rust blooming 

d) Rogue peak, Key, Amplitude, Peak to through 

 

82. Degree of cleanliness not depends 

a) Time spent on area 

b) Angle of impingement 

c) Velocity of the particles 

d) Substrate rust grade 

 

83. The standard for sizing of abrasives is 

a) BS 7079 

b) BS 410 

c) BGC/PS/PA10 

d) SI 1657 

 

84. The force required to separate two surfaces in touch. 

a) Profile 

b) Adhesion

c) Anchor pattern 

d) Amplitude 

 

85. The two theories of adhesion are 

a) Molecular interference and molecular attraction 

b) Molecular integration and molecular connection 

c) Molecular cross linking and molecular coalescence 

d) Microscopic interaction and microscopic collaboration 

 

86. Another names of profile is? 

a) Anchor pattern 

b) Key 

c) Amplitude 

d) All of the above 

 

87. Amplitude refers to what? 

a) The peak to through height of a blast profile 

b) The height required for scaffolding prior to blast cleaning 

c) The velocity of abrasive particles 

d) The roughness of an abrasive particle 

 

88. Anchor pattern, key, peak-to-through height and amplitude are names given to what? 

a) The abrasive properties 

b) The cross section of a blasted area 

c) The total area of blasted substrate 

d) The potential of adhesion 

 

89. Degree of roughness related to 

a) Abrasive blasting 

b) Hand and power tool 

c) Anchor pattern 

d) Abrasive hardness

 

90. Flash Rust 

a) Due to rogue peak 

b) Due to Moisture 

c) Due to air temperature

d) Due to steel temperature 


91.       Profile thickness as per BGAS

a)         30-75 microns

b)         25-100 microns

c)         30-70 microns

d)         25-70 microns

 

92.       Blasting in one area for too long, produces what?

a)         Hackles

b)         Rogue Peaks

c)         Silvers

d)         Laminations

 

93.       Longitudinal crack is called

a)         Laminations (slivers)

b)         Hackles

c)         Rogue peaks

d)         Amplitude

 

94.       Surface profile thickness is measured by?

a)         Comparators

b)         Digital profile needle gauge

c)         Surface profile needle gauge

d)         Dial micrometer with replica tape

 

95.       Surface needle gauge calibrated by

a)         Blasted surface

b)         Smooth piece of glass

c)         Bare metal

d)         Coated metal

 

96.       Replica tape supplied in grades

a)         Coarse and Extra Coarse

b)         Coarse and fine coarse

c)         Extra coarse and medium coarse

d)         Coarse and below coarse

 

97.       Trade name of Replica tape

a)         Mylar

b)         Paper

c)         Testex

d)         Polyester

 

98.       Testex also called

a)         Mylar

b)         Paper

c)         Polyester

d)         Corn plaster

 

99.       Thickness of Replica tape

a)         20 microns

b)         40 microns

c)         50 microns

d)         30 microns

 

100.     What is the material used in surface replica tape, used to measure profile?

a)         Mylex

b)         Testrex

c)         Mylar

d)         Mylon


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