The hardness of a grinding wheel is determined by the
Hardness of abrasive grains
Ability of the bond to retain abrasives
Hardness of the bond
Ability of the grinding wheel to penetrate the work piece
Correct Answer :
B. Ability of the bond to retain abrasives
Related Questions
The machining of titanium is difficult due to
High thermal conductivity of titanium
Chemical reaction between tool and work
Low tool-chip contact area
None of these
The lathe spindles are usually made hollow and provided with
Internal taper
External taper
Internal and external taper
No taper
Shrinkage allowance on pattern is provided to compensate for shrinkage when
The temperature of liquid metal drops from pouring to freezing temperature
The metal changes from liquid to solid state at freezing temperature
The temperature of solid phase drops from freezing to room temperature
The temperature of metal drops from pouring to room temperature
In DC arc welding, if leads are arranged in work as Negative pole of the welding arc and electrode as Positive pole of the welding arc, the arrangement is known as
Fusion
Reverse polarity
Forward welding
Direct polarity
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
The velocity of tool along the tool face is known as
Shear velocity
Chip velocity
Cutting velocity
Mean velocity
Which of the following statement is wrong?
The diamond is the hardest tool material and can run at cutting speeds about 50 times that of high speed steel tool.
The ceramic tools can be used at cutting speeds 40 times that of high speed steel tools.
The cemented carbide tools can be used at cutting speeds 10 times that of high speed steel tools.
The ceramic tools can withstand temperature upto 600°C only.
The drill spindles are provided with standard taper known as
Morse taper
Seller's taper
Chapman taper
Brown and Sharpe taper
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
When two main plates are kept in alignment butting each other and riveted with cover plate on both sides of the main plates with two rows of rivets in each main plate, the joint is known as _______ double cover butt joint.
Single riveted
Double riveted
Both (A) and (B)
None of these
The relation between tool life (T) and cutting speed (V) is VTn = Constant. In this relation, the value of n depends upon
Work material
Tool material
Working conditions
Type of chip produced
A bottoming tap has
Its end tapered for about three or four threads
Its end tapered for about eight or ten threads
Full threads for the whole of its length
None of the above
Which of the following parameters govern the value of shear angle in continuous chip formation?
True feed
Chip thickness
Rake angle of the cutting tool
All of these
The cutting tool in a milling machine is mounted on
Spindle
Arbor
Column
Knee
The saw milling is an operation of
Producing grooves around the periphery of a cylindrical or conical workpiece
Producing narrow slots or grooves on a workpiece
Reproduction of an outline of a template on a workpiece
Machining several surfaces of a workpiece simultaneously
The actual feed in centerless grinders is given by (where d = Dia. of regulating wheel, n = Revolutions per minute, and α = Angle of inclination of wheel)
πd
πdn
πdn sinα
πdn cosα
Glazing in grinding wheels can be decreased by
Using a harder wheel or by increasing the wheel speed
Using a softer wheel or by decreasing the wheel speed
Using a harder wheel or by decreasing the wheel speed
Using a softer wheel or by increasing the wheel speed
The method of grinding used to produce internal cylindrical holes and tapers, is
Internal cylindrical grinding
Form grinding
External cylindrical grinding
Surface grinding
The tool material, for faster machining, should have
Wear resistance
Red hardness
Toughness
All of these
The soft grade grinding wheels are denoted by the letters
A to H
I to P
Q to Z
A to P
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
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
The high cutting speed and large rake angle of the tool will result in the formation of
Continuous chips
Discontinuous chip
Continuous chips with built up edge
None of these
The specific cutting energy used for establishing the machinability of the metal depends upon its
Coefficient of friction
Microstructure
Work hardening characteristics
All of these
For machining a mild steel workpiece using carbide tool, the maximum material will be removed at a temperature of
50°C
100°C
175°C
275°C
The common welding error that occurs due to shrinkage of weld metal, faulty clamping of parts, faulty penetration or overheating at joints is called?
Distortion
Warping
Porous weld
Poor fusion
The point angle of a drill, for drilling stainless steel, is
90°
118°
135°
150°
Which one of the following is a solid state joining process?
Gas tungsten arc welding
Resistance spot welding
Friction welding
Submerged arc welding
In order to prevent tool from rubbing the work _________ on tools are provided.
Rake angles
Relief angles
Face angles
None of these
A CNC vertical milling machine has to cut a straight slot of 10 mm width and 2mm depth by a cutter of 10 mm diameter between points (0,0) and (100,100) on the XY plane (dimensions in mm). The feed rate used for milling is 50 mm/min, milling time for the slot (in seconds) is
120
170
180
240