In welding copper alloys with TIG arc welding
Direct current with straight polarity is used
Direct current with reversed polarity is used
Alternating current is used
Any one of these
Correct Answer :
A. Direct current with straight polarity is used
Related Questions
In a unilateral system of tolerance, the tolerance is allowed on
One side of the actual size
One side of the nominal size
Both sides of the actual size
Both sides of the nominal size
The dowels are
Wooden nails
Box nails
Wire nails
None of these
In ________ welding, the weld may be made either from left to right or from right to left.
Forehand
Backhand
Vertical
None of these
Which one of the following material will require the largest size of riser for the same size of casting?
Aluminium
Cast iron
Steel
Copper
The binder commonly used in making oil sand, is
Clay type binder
Organic type binder
Inorganic type binder
Any one of these
The algebraic difference between the minimum limit and the basic size is called
Actual deviation
Upper deviation
Lower deviation
Fundamental deviation
The welding set up is said to have straight polarity, when
Work is connected to the positive terminal and the electrode holder to the negative terminal
Work is connected to the negative terminal and the electrode holder to the positive terminal
Work is connected to the positive terminal and the electrode holder is earthed
Work is connected to the negative terminal and the electrode holder is earthed
In sheet metal work, he cutting force on the tool can be reduced by
Grinding the cutting edges sharp
Increasing the hardness of tool
Providing shear on tool
Increasing the hardness of die
For obtaining a cup of diameter 25 mm and height 15 mm by drawing, the size of the round blank should be approximately
42 mm
44 mm
46 mm
48 mm
Structural sections such as rails, angles, I-beams are made by
Hot rolling
Hot drawing
Hot piercing
Hot extrusion
In forehand welding, the angle between the welding rod and the work is kept as
30°-40°
40°-50°
50°-60°
60°-70°
The property of sand due to which the sand grains stick together is called
Collapsibility
Permeability
Cohesiveness
Adhesiveness
Galvanising is a
Zinc diffusion process
Process of coating zinc by hot dipping
Process used for making thin phosphate coating on steel
None of the above
The surface to be machined is marked on the pattern by
Red colour
Yellow colour
Black colour
Blue colour
The edge of a steel plate cut by oxygen cutting will get hardened when the carbon content is
Less than 0.1 percent
Less than 0.3 percent
More than 0.3 percent
Anywhere between 0.1 to 1 percent
In a cold chamber die casting machine, only nonferrous alloys with _________ are casted.
Low melting temperature
High melting temperature
Both (A) and (B)
None of these
A ring gauge is used to
Check the diameter of shafts or studs
Test the accuracy of holes
Check the clearance between two mating surfaces
All of the above
In electric resistance welding, pressure applied varies from
1 to 5 MPa
5 to 10 MPa
10 to 25 MPa
25 to 55 MPa
The metal patterns as compared to wooden patterns require less
Shrinkage allowance
Machining allowance
Draft allowance
Distortion allowance
A taper provided on the pattern for its easy and clean withdrawal from the mould is known as
Machining allowance
Draft allowance
Shrinkage allowance
Distortion allowance
The tolerance produced by shell moulding process of casting is
+0.05 mm
±0.2 mm
+0.5 mm
±1 mm
The consumable electrode is used in
Carbon arc welding
Submerged arc welding
TIG arc welding
MIG arc welding
The operation of cutting a sheet of metal in a straight line along the length, is known as
Plunging
Notching
Slitting
Forming
For gas welding, the pressure desired at the welding torch for acetylene is
7 to 103 kN/m²
70 to 280 kN/m²
280 to 560 kN/m²
560 to 840 kN/m²
The minimum size of a bloom is
5 cm × 5 cm
10 cm × 10 cm
15 cm × 15 cm
20 cm × 20 cm
The surface to be left unmachined is marked on the pattern by
Red colour
Yellow colour
Black colour
Blue colour
For welding plates of thickness less than 5 mm, its edges
Do not require bevelling
Should be bevelled to a single-V or U-groove
Should have a double-V or U-groove on one side
Should have a double-V or U-groove on both sides
Lancing is the operation of
Cutting a sheet of metal in a straight line along the length
Removal of metal to the desired shape from the edge of a plate
Cutting a sheet of metal through part of its length and then bending the cut portion
Bending a sheet of metal along a curved axis
A jolt machine is used to
Ram the sand harder at the pattern face with decreasing hardness towards the back of the mould
Ram the sand harder at the back of the mould and softer on the pattern face
Produce uniform sand hardness throughout the mould
Produce uniform packing of sand in the mould
The operation of straightening a curved sheet metal, is known as
Drawing
Squeezing
Coining
Planishing