The maximum possible draft in cold rolling of sheet increases with the
Increase in coefficient of friction
Decrease in coefficient of friction
Decrease in roll radius
Decrease in roll velocity
Correct Answer :
A. Increase in coefficient of friction
Related Questions
A hole is of dimension φ = 9 ₊0⁺⁰⁰¹⁵ mm. The corresponding shaft is of dimension φ = 9 ₊0.001⁺⁰⁰¹⁰ mm. The resulting assembly has
Loose running fit
Close running fit
Transition fit
Interference fit
If the flame of the welding torch is directed towards the progress of welding, then what will you call the welding technique?
Forehand welding
Flux cored ARC welding
Electro slag welding
Pulsed spray welding
Grinding wheels should be tested for balance
Only at the time of manufacture
Before starting the grinding operation
At the end of grinding operation
Occasionally
High speed steel tools retain their hardness upto a temperature of
250°C
350°C
500°C
900°C
In a plain milling cutter, the chip space between the back of one tooth and the face of the next tooth is called
Face
Fillet
Gash
Land
In metal machining, the zone where the heat is generated due to friction between the moving chip and the tool face, is called
Friction zone
Work-tool contact zone
Shear zone
None of these
Chemical milling operation is performed
On universal milling machine
On plain milling machine
In a tank containing an etching solution
Any one of these
Two 1 mm thick steel sheets are to be spot welded at a current of 5000 A. Assuming effective resistance to be 200 μm and current flow time of 0.2 second, heat generated during the process will be
0.2 Joule
1 Joule
5 Joule
1000 Joule
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
A jig is defined as a device which
Holds and locates a workpiece and guides and controls one or more cutting tools
Holds and locates a workpiece during an inspection or for a manufacturing operation
Is used to check the accuracy of workpiece
All of the above
Broaching is applied for machining
Internal and external surfaces
Round or irregular shaped holes
External flat and contoured surfaces
All of these
Gear burnishing is a process for
Surface finishing
Undercut gears
Cycloidal gears
Removing residual stresses from teeth roots
The angle between the lathe centres is
30°
45°
60°
90°
Friction at the tool-chip interface can be reduced by
Decreasing the rake angle
Increasing the depth of cut
Decreasing the cutting speed
Increasing the cutting speed
A better machinable metal is one which gives
Lower chip-tool contact area and larger shear angle
Higher chip-tool contact area and smaller shear angle
Lower chip-tool contact area and smaller shear angle
Higher chip-tool contact area and larger shear angle
For machining a cast iron workpiece by a high speed steel tool, the average cutting speed is
10 m/min
15 m/min
22 m/min
30 m/min
The relation between the tool life (T) in minutes and cutting speed (V) in m/min is (where n = An exponent, which depends upon the tool and workpiece, and C = A constant)
VnT = C
VTn = C
Vn/T = C
V/Tn = C
When the shear angle is small
Path of shear is short and chip is thin
Path of shear is large and chip is thick
Path of shear is short and chip is thick
Path of shear is large and chip is thin
A __________ grinding wheel is used to grind soft materials.
Course grained
Medium grained
Fine grained
None of these
The swing diameter over the bed is ________ the height of the centre measured from the bed of the lathe.
Equal to
Twice
Thrice
One-half
The obtuse angle, included between the chisel edge and the lip as viewed from the end of a drill, is called
Helix or rake angle
Point angle
Chisel edge angle
Lip clearance angle
In order to have interference fit, it is essential that the lower limit of the shaft should be
Greater than the upper limit of the hole
Lesser than the upper limit of the hole
Greater than the lower limit of the hole
Lesser than the lower limit of the hole
Which of the following process is used for preparing parts having large curved surfaces and thin sections?
Hot machining
Ultrasonic machining
ECM process
Chemical milling
A tool used to withdraw a drill from the sleeve is called
Drill remover
Drill puller
Drift
Drill drawer
In the relation VTn = C, the value of n for carbide tools is
0.1 to 0.2
0.20 to 0.25
0.25 to 0.40
0.40 to 0.55
The tool life in case of a grinding wheel is the time
Between two successive regrinds of the wheel
Taken for the wheel to be balanced
Taken between two successive wheel dressings
Taken for a wear of 1 mm on its diameter
Ceramic cutting tools are
Made by cold pressing of aluminium oxide powder
Available in the form of tips
Brittle and have low bending strength
All of these
The taper on the lathe spindle is
1 in 10
1 in 15
1 in 20
1 in 30
Two plates of the same metal having equal thickness are to be butt welded with electric arc. When the plate thickness changes, welding is achieved by
Adjusting the current
Adjusting the duration of current
Changing the electrode size
Changing the electrode coating
The operation of producing grooves around the periphery of a cylindrical or conical workpiece is called
Profile milling
Gang milling
Saw milling
Helical milling