The primary purpose of a sprue in a casting mould is to
Feed the casting at a rate consistent with the rate of solidification.
Act as a reservoir for molten metal
Feed molten metal from the pouring basin to the gate
Help feed the casting until all solidification takes place
Correct Answer :
C. Feed molten metal from the pouring basin to the gate
Related Questions
In a plain milling cutter, the portion of the gash adjacent to the cutting edge on which the chip impinges is called
Face
Fillet
Land
Lead
The grade of grinding wheel depends upon
Hardness of the material being ground
Speed of wheel and work
Condition of grinding machine
All of these
In orthogonal turning of a low carbon steel bar of diameter 150 mm with uncoated carbide tool, the cutting velocity is 90 m/min. The feed is 0.24 mm/rev and the depth of cut is 2mm. The chip thickness obtained is 0.48 mm. If the orthogonal rake angle is zero and the principle cutting edge angle is 90⁰, the shear angle in degree is
20.56
26.56
30.56
36.56
The abrasive slurry used in ultrasonic machining contains fine particles of
Aluminium oxide
Boron carbide
Silicon carbide
Any one of these
In which of the following machine, the work is usually rotated while the drill is fed into work?
Sensitive drilling machine
Radial drilling machine
Gang drilling machine
Deep hole drilling machine
The depth of cut in drilling is __________ the drill diameter.
Equal to
One-fourth
One-half
Double
The snag grinding is done
To produce good surface finish and high degree of accuracy
To remove considerable amount of metal without regard to accuracy of the finished surface
To grind exterior cylindrical surfaces
Any one of the above
In machining metals, chips break due to __________ of work material.
Toughness
Ductility
Elasticity
Work hardening
The effect of setting a boring tool above centre height leads to
Increase in the effective rake angle and a decrease in the effective clearance angle
Increase in both effective rake angle and effective clearance angle
Decrease in the effective rake angle and an increase in the effective clearance angle
Decrease in both effective rake angle and effective clearance angle
If the helix angle of the drill is made _________ 30°, then the torque required to drive the drill at a given feed will be more.
Equal to
Less than
More than
None of these
In down milling, the thickness of chip is
Minimum at the beginning of the cut and maximum at the end of the cut
Maximum at the beginning of the cut and minimum at the end of the cut
Uniform throughout the cut
None of these
The top and sides of the table of a shaper usually have
L-type slots
T-type slots
I-type slots
Any one of these
The cutting speed is maximum while machining __________ with a high speed steel tool.
Cast iron
Mild steel
Brass
Aluminium
In metal cutting operations, the shear angle is the angle made by the shear plane with the
Direction of the tool axis
Direction of tool travel
Perpendicular to the direction of the tool axis
Central plane of the workpiece
Cutting fluids are used to
Cool the tool
Improve surface finish
Cool the workpiece
All of these
The chuck used for setting up of heavy and irregular shaped work should be
Four jaw independent chuck
Three jaw universal chuck
Magnetic chuck
Drill chuck
In centreless grinding, work place centre will be
Above the line joining the two wheel centres
Below the line joining the two wheel centres
On the line joining the two wheel centres
At the intersection of the line joining the wheel centres with the work place plane
Surface grinding is done to produce
Tapered surface
Flat surface
Internal cylindrical holes
All of these
What type of fusion welding process is used for welding sheet metals of all engineering metals (except Cu, Ag) in automobile and air craft industries, pipe and tubing production?
Thermit welding
Electroslag welding
Resistance welding
Submerged arc welding
In a metal arc welding process, metal transfer across the arc may take place by a method of material transfer where the metal transfers across the arc is in larger drops. This is at the rate of 100 drops / sec or less, what is this known as
Globular transfer
Spray transfer
GMAW practice
Dip transfer
The cutting fluid mostly used for machining alloy steels is
Water
Soluble oil
Dry
Sulphurised mineral oil
What is the type of shielding gas for GTAW (Gas Tungsten Arc Welding) used for carbon steels only called?
Argon H₂
Argon CO₂
Argon Helium
Helium
In a particular type of welding, flux is prepared in the form of a coarse powder and granulated flux is spread over the joint. What is this type of welding process called?
Electric arc welding
Submerged arc welding
MIG welding
TIG welding
The abrasive recommended for grinding materials of low tensile strength is
Silicon carbide
Aluminium oxide
Sand stone
Diamond
When the end of a tap is tapered for about three or four threads, it is known as a
Taper tap
Bottoming tap
Second tap
None of these
If the tearing efficiency of a riveted joint is 50%, then ratio of rivet hole diameter to the pitch of rivets is
0.20
0.30
0.50
0.60
In reaming process
Metal removal rate is high
High surface finish is obtained
High form accuracy is obtained
High dimensional accuracy is obtained
The silicon carbide abrasive is chiefly used for grinding
Cemented carbide
Ceramic
Cast iron
All of these
Crater wear leads to
Increase in cutting temperature
Weakening of tool
Friction and cutting forces
All of these
Volume of a cube of side l and volume of a sphere of radius r are equal. Both the cube and the sphere are solid and of same material. They are being cast. The ratio of the solidification time of the cube to the same of the sphere is
(4π/6)³ × (r/l)⁶
(4π/6) × (r/l)²
(4π/6)² × (r/l)³
(4π/6)² × (r/l)⁴