Objective Questions on Mechanical Engineering

85-The ratio between oxygen and acetylene gases for neutral flame in gas welding is:

(A) 2:1

(B) 1:1

(C) 1:2

(D) 4:1

 

86-Thermit, used in Thermit welding process is a mixture of:

(A) Charcoal and Aluminium

(B) Aluminium and Iron oxide

(C) Charcoal and Iron oxide

(D) Charcoal, Aluminium and Iron oxide

 

87-The temperature developed during a Thermit welding process is of the order of

(A) 1500°C

(B) 2000°C

(C) 3000°C

(D) 4000°C

 

88-The current value in the arc welding is decided by:

(A) Speed of travel

(B) Plate thickness

(C) Welded length

(D) Electrode size

 

89-Which of the following welding methods uses pool of molten metal?

(A) Submerged arc welding

(B) Resistance welding

(C) TIG

(D) MIG

 

90-The welding zone in the TIG arc welding is shielded by an atmosphere of:

(A) Oxygen gas

(B) CO2

(C) Hydrogen

(D) Helium

 

91-Which of the following welding techniques uses a non consumable electrode?

(A) MIG

(B) TIG

(C) Submerged arc

(D) Thermit

 

92-Vacuum environment is required in:

(A) Ultrasonic welding

(B) Laser beam welding

(C) Electron beam welding

(D) None

 

93-High beam electron beam in electron beam welding is focused on the weld spot using:

(A) Vacuum lens

(B) Inert gas lens

(C) Optical lens

(D) Magnetic lens

 

94-Weld spatter is

(A) A welding defect

(B) An electrode

(C) A flux

(D) None

 

95-In foundry, which sand is used for making cores?

(A) Oil sand

(B) Green sand

(C) Loam sand

(D) Parting sand

 

96-The operation of cutting a piece out of stock material to a predetermined contour is termed as:

(A) Drawing

(B) Piercing

(C) Punching

(D) Blanking

 

ANSWERS:

85-(B), 86-(B), 87-(C), 88-(D), 89-(A), 90-(D), 91-(B), 92-(C), 93-(D), 94-(A), 95-(B), 96-(D)