Different Machining Processes MCQ Quiz - Objective Question with Answer for Different Machining Processes - Download Free PDF

Last updated on Jun 27, 2025

Latest Different Machining Processes MCQ Objective Questions

Different Machining Processes Question 1:

Which of the following interactions is expected to produce chip during a grinding process?

  1. Chip-bond
  2. Bond-workpiece 
  3. Chip-workpiece
  4. Grit-workpiece

Answer (Detailed Solution Below)

Option 4 : Grit-workpiece

Different Machining Processes Question 1 Detailed Solution

Explanation:

Grinding Process:

  • Grinding is a machining process that uses an abrasive wheel as the cutting tool to remove material from a workpiece surface. The abrasive grains on the grinding wheel's surface act as cutting edges, interacting with the workpiece to produce chips. This process is widely used in manufacturing for precision machining, finishing surfaces, and achieving tight tolerances. The interaction that primarily produces chips during grinding involves the abrasive grit and the workpiece material.

Grit-workpiece

  • The interaction between the grit and the workpiece is responsible for the removal of material in the form of chips during the grinding process. The abrasive grits embedded in the grinding wheel's surface serve as cutting tools. When the grinding wheel rotates and comes into contact with the workpiece, the abrasive grits cut into the material, shearing off tiny chips. This cutting mechanism is similar to conventional machining processes, where a cutting tool removes material to shape the workpiece. The following steps outline how this interaction produces chips:
    • Contact between Grit and Workpiece: As the grinding wheel rotates, individual abrasive grits come into contact with the workpiece surface. The pressure exerted by the wheel forces the grits into the material.
    • Material Penetration: The sharp edges of the abrasive grits penetrate the workpiece surface, removing material in the form of chips. The depth of penetration depends on factors such as grit size, wheel speed, feed rate, and the material properties of the workpiece.
    • Chip Formation: The material undergoes plastic deformation and shearing due to the high-pressure and high-speed interaction between the grit and the workpiece. This results in the formation of small chips, which are carried away by the grinding wheel or coolant.
    • Surface Finish: The continuous engagement of abrasive grits with the workpiece surface generates a smooth and precise finish. The size and distribution of the grits significantly influence the surface quality and material removal rate.

Different Machining Processes Question 2:

What type of abrasive is suitable for grinding glass and ceramic materials?

  1. Copper boron nitride 
  2. Silicon carbide
  3. Magnesium oxide
  4. Diamond

Answer (Detailed Solution Below)

Option 2 : Silicon carbide

Different Machining Processes Question 2 Detailed Solution

Explanation:

Silicon Carbide:

Silicon carbide (SiC) is a highly effective and widely used abrasive material for grinding glass and ceramic materials. This is due to its unique combination of properties that make it ideal for such applications. Below is a detailed explanation of why silicon carbide is the correct choice for this purpose:

1. High Hardness:

  • Silicon carbide is an extremely hard material, with a Mohs hardness of approximately 9.5. This makes it one of the hardest materials available, second only to diamond and a few other rare substances. The high hardness of silicon carbide allows it to effectively grind and shape glass and ceramics, which are also very hard and brittle materials.

2. Abrasion Resistance:

  • Silicon carbide exhibits excellent wear and abrasion resistance. This property ensures that the abrasive particles remain effective over extended periods of use, making it a durable and cost-efficient choice for grinding operations.

3. Sharp Cutting Edges:

  • Silicon carbide abrasives have sharp and angular cutting edges. These sharp edges enable precise and efficient material removal during grinding, making it suitable for applications that require high precision, such as in the finishing and shaping of glass and ceramic surfaces.

4. Thermal Stability:

  • During grinding, the friction between the abrasive and the workpiece generates heat. Silicon carbide has excellent thermal stability, meaning it can withstand high temperatures without losing its structural integrity or cutting efficiency. This property is particularly important for grinding glass and ceramics, as these materials are sensitive to thermal stress and can crack or deform under excessive heat.

5. Chemical Inertness:

  • Glass and ceramics often contain reactive components that can interact with certain abrasives. Silicon carbide is chemically inert and does not react with these materials, ensuring that the grinding process does not compromise the chemical composition or quality of the workpiece.

6. Versatility:

  • Silicon carbide is available in various grit sizes, allowing it to be used for both coarse grinding and fine polishing. This versatility makes it suitable for a wide range of applications, from rough surface preparation to achieving a mirror-like finish on glass and ceramics.

Applications of Silicon Carbide in Grinding:

  • Shaping and finishing optical lenses and mirrors.
  • Grinding and polishing ceramic tiles and components.
  • Cutting and shaping glass for decorative and industrial purposes.
  • Surface preparation of ceramics used in electronic and medical devices.

Different Machining Processes Question 3:

In the up-milling process, the metal is removed in the form of small chips by a cutter rotating _____.

  1. against the direction of the travel of the workpiece
  2. perpendicular to the direction of the travel of the workpiece
  3. in the same direction of the feed of the workpiece
  4. Metal will not be removed in the milling process.

Answer (Detailed Solution Below)

Option 1 : against the direction of the travel of the workpiece

Different Machining Processes Question 3 Detailed Solution

Explanation:

Up-Milling Process

  • The up-milling process, also known as conventional milling, is one of the two main methods used in milling operations. In this process, the cutting tool rotates against the direction of the feed of the workpiece. This means that the cutter teeth engage the material at the beginning of the cut with a small chip thickness, which increases progressively to the maximum thickness as the tool leaves the material.
  • During the up-milling process, the cutting tool pushes the workpiece in the opposite direction of its feed. This results in a gradual buildup of chip thickness, which is advantageous for certain types of machining operations. The cutter tends to push the workpiece away from the tool, which can lead to vibrations if the setup is not rigid. The process generally requires more force to cut as compared to down-milling.

Key Characteristics of Up-Milling:

  • The cutting tool rotates against the direction of the feed of the workpiece.
  • Chip thickness starts small and increases as the cutter progresses.
  • It is suitable for machining materials with hard surfaces or for rough cutting operations.
  • The cutting force tends to lift the workpiece, requiring a firm clamping setup to avoid movement or vibrations.
  • Tool wear is relatively higher compared to down-milling due to the increased friction at the start of the cut.

Applications:

  • Used in machining operations where a rough surface finish is acceptable.
  • Preferred for machining workpieces with abrasive or hardened surfaces, as the gradual engagement of the tool reduces the initial impact.
  • Commonly used for milling operations on uneven or dirty workpiece surfaces.

Different Machining Processes Question 4:

What bond is commonly employed in super abrasive grinding wheels? 

  1. Oxychloride bond
  2. Shellac bond
  3. Brazed bond
  4. Metal bond

Answer (Detailed Solution Below)

Option 4 : Metal bond

Different Machining Processes Question 4 Detailed Solution

Explanation:

Super Abrasive Grinding Wheels and Metal Bond

  • Grinding wheels are essential tools in the manufacturing industry, used for cutting, grinding, and finishing operations. Super abrasive grinding wheels are a specialized category of grinding wheels designed for applications that require exceptional hardness, durability, and precision. These wheels are made using super abrasive materials such as diamond and cubic boron nitride (CBN). To ensure the effective performance of these wheels, the choice of the bonding material is critical. Among the various bonding options available, the metal bond is commonly employed for super abrasive grinding wheels.
  • Metal bonds are known for their strength, durability, and ability to hold abrasive grains securely in place. This makes them an ideal choice for applications involving high-pressure and high-temperature grinding operations. Let’s delve into the characteristics and advantages of metal bonds, as well as their role in super abrasive grinding wheels.

Characteristics of Metal Bonds:

  • Metal bonds are made from various metals or metal alloys, such as bronze, tungsten, or steel, which are fused together to form a strong and rigid matrix.
  • They exhibit excellent thermal conductivity, which helps to dissipate heat generated during grinding operations, thereby reducing the risk of thermal damage to the workpiece.
  • Metal bonds provide high wear resistance, enabling them to maintain their shape and dimensional accuracy over extended periods of use.
  • The rigidity of metal bonds ensures that the abrasive grains are held firmly, allowing for precise and consistent material removal.

Advantages of Metal Bonds in Super Abrasive Grinding Wheels:

  • Durability: Metal bonds are highly durable and can withstand the extreme conditions of super abrasive grinding, making them suitable for applications requiring prolonged tool life.
  • Precision: The rigid structure of metal bonds ensures that the abrasive grains remain fixed in place, enabling precise grinding operations with minimal deviation.
  • Thermal Stability: The excellent thermal conductivity of metal bonds helps in managing the heat generated during grinding, preventing thermal damage to both the tool and the workpiece.
  • Versatility: Metal bonds can be customized to suit specific grinding applications by adjusting the composition and properties of the metal matrix.

Applications of Metal Bonded Super Abrasive Grinding Wheels:

  • Tool and Die Making: Metal bonded grinding wheels are used for precision grinding of cutting tools, molds, and dies.
  • Aerospace Industry: These wheels are employed in the aerospace sector for grinding hard-to-machine materials like titanium and nickel-based alloys.
  • Automotive Industry: Metal bonded wheels are used for grinding components such as engine parts, transmission gears, and brake discs.
  • Electronics Industry: They are used in the manufacturing of semiconductor components, where high precision and surface finish are critical.

Different Machining Processes Question 5:

Parallel shank type and morse taper shank type drills belong to _____ type of drills. 

  1. twist
  2. hexagonal
  3. straight-fluted
  4. flat

Answer (Detailed Solution Below)

Option 1 : twist

Different Machining Processes Question 5 Detailed Solution

Explanation:

Drills:

  • Drills are cutting tools used to create cylindrical holes in a workpiece. They come in various types, each suited for specific applications. Among the diverse range of drills, parallel shank type and Morse taper shank type drills are categorized under twist drills. Twist drills are the most commonly used drills in manufacturing and engineering industries due to their versatility and efficiency.

Twist Drills:

Twist drills are characterized by their helical grooves or flutes that run along the length of the drill body. These flutes serve multiple purposes, such as:

  • Removing Chips: The helical design helps in removing chips and debris from the drilled hole, ensuring smooth operation.
  • Guiding Coolant: The flutes allow coolant or lubricants to flow to the cutting edge, reducing heat and improving performance.
  • Maintaining Cutting Edge: The design ensures that the cutting edge remains sharp and effective during operation.

Twist drills are available in different shank types, each designed for specific applications:

  • Parallel Shank Type: These drills have a uniform diameter throughout the shank. They are commonly used with chucks or holders and are suitable for general-purpose drilling operations.
  • Morse Taper Shank Type: These drills have a tapered shank that fits directly into the spindle or machine tool without the need for a chuck. They are used for heavy-duty applications and provide better torque transmission.

Top Different Machining Processes MCQ Objective Questions

A straight teeth slab milling cutter of 100 mm diameter and 10 teeth rotating at 150 r.p.m. is used to remove a layer of 3 mm thickness from a steel bar. If the table feed is 400 mm/minute, the feed per tooth in this operation will be:

  1. 0.26 mm
  2. 0.4 mm
  3. 0.5 mm
  4. 0.6 mm

Answer (Detailed Solution Below)

Option 1 : 0.26 mm

Different Machining Processes Question 6 Detailed Solution

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Concept:

Table speed in mm/minute = f× Z × N

where, N = RPM, Z = no. of teeth, ft = Feed per tooth

Calculation:

Given:

Z = 10, N = 150 rpm, ft = ?, fm = 400 mm/min

Table speed in mm/minute, 400 = 150 × 10 × ft

ft = 0.26 mm

A grinding wheel gets glazed due to

  1. Wear of abrasive grains
  2. Wear of bond
  3. Breaking of abrasives
  4. Cracks in wheel

Answer (Detailed Solution Below)

Option 1 : Wear of abrasive grains

Different Machining Processes Question 7 Detailed Solution

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Explanation:

Glazing: When a surface of the wheel develops a smooth and shining appearance, it is said to be glazed. This indicates that the wheel is blunt, i.e. the abrasive grains are not sharp.

  • Glazing is caused by grinding hard materials on a wheel that has too hard a grade of bond. The abrasive particles become dull owing to cutting the hard material. The bond is too firm to allow them to break out. The wheel loses its cutting efficiency.
  • Glazing of grinding wheel is more predominant in hard wheels with higher speeds. With softer wheels and relatively lower speeds, this effect is less prominent.

Which bond is used in grinding wheels for the very high-class surface finish with close dimensional accuracy?

  1. Rubber bond
  2. Vitrified bond
  3. Silicate bond
  4. Oxychloride bond

Answer (Detailed Solution Below)

Option 1 : Rubber bond

Different Machining Processes Question 8 Detailed Solution

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Concept:

Abrasive grains are held together in a grinding wheel by a bonding material. The bonding material does not cut during the grinding operation. Its main function is to hold the grains together with varying degrees of strength. Standard grinding wheel bonds are silicate, vitrified, resinoid, shellac, rubber and metal.

Rubber bond (R): 

  • Rubber-bonded wheels are extremely tough and strong.
  • Their principal uses are as thin cut-off wheels and driving wheels in centerless grinding machines.
  • They are used also when extremely fine finishes are required on bearing surfaces.

Silicate bond (S): 

  • This bonding material is used when the heat generated by grinding must be kept to a minimum. 
  • Silicate bonding material releases the abrasive grains more readily than other types of bonding agents. 
  • This is the softest bond in grinding wheel.

Vitrified bond (V): 

  • Vitrified bonds are used on more than 75 per cent of all grinding wheels.
  • Vitrified bond material is comprised of finely ground clay and fluxes with which the abrasive is thoroughly mixed.

Resinoid bond (B): 

  • Resinoid bonded grinding wheels are second in popularity to vitrified wheels.
  • The phenolic resin in powdered or liquid form is mixed with the abrasive grains in a form and cured at about 360F.

Shellac bond (E): 

  • It's an organic bond used for grinding wheels that produce very smooth finishes on parts such as rolls, cutlery, camshafts and crankpins.
  • Generally, they are not used on heavy-duty grinding operations.

Metal bond (M): 

  • Metal bonds are used primarily as binding agents for diamond abrasives.
  • They are also used in electrolytic grinding where the bond must be electrically conductive.

G-ratio varies from ________ in very rough grinding. 

  1. 11.0 to 15.0
  2. 6.0 to 10.0
  3. 1.0 to 5.0
  4. 16.0 to 20.0

Answer (Detailed Solution Below)

Option 3 : 1.0 to 5.0

Different Machining Processes Question 9 Detailed Solution

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Explanation:

  • Grinding involves an Abrasive action and while removing material abrasive also wears out and when the rubbing force reaches the threshold, the worn-out abrasives are pulled out of the wheel.
  • Thereby giving chance to a fresh layer of abrasives for removing material. This is known as the self-sharpening behavior of the grinding wheel.
  • The ratio of the volume of material removed to the volume of wheel wear is known as grinding ratio.

Grindingratio=VmVw=l×b×dπ4×w×(Di2Df2),wherew=widthofwheel

  • The grinding ratio varies from 1.0 - 5.0 in very rough grinding.

Which of the following is not a natural abrasive?

  1. Garnet
  2. Emery
  3. Boron-carbide
  4. Corundum

Answer (Detailed Solution Below)

Option 3 : Boron-carbide

Different Machining Processes Question 10 Detailed Solution

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Explanation:

Abrasives are classified into two categories:

Natural Abrasives:

  • Garnet, Corundum, Emery (impure corundum), Calcite (calcium carbonate), Diamond dust, Novaculite, Pumice, Rouge, Sand, Sandstone, Tripoli, Powdered feldspar, Staurolite

Synthetic Abrasives:

  • Boron carbide, Borazon (cubic boron nitride or CBN), Ceramic, Ceramic aluminium oxide, Ceramic iron oxide, Dry ice, Glass powder, Steel abrasive, Zirconia alumina, Slags

A grinding wheel is specified by C 70 G 7 R 23 Here C stands for:

  1. Diamond
  2. Silicon carbide
  3. Cubic boron nitride
  4. Aluminium oxide

Answer (Detailed Solution Below)

Option 2 : Silicon carbide

Different Machining Processes Question 11 Detailed Solution

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Concept:

A grinding wheel consists of the abrasive that does the cutting, and the bond that holds the abrasive particles together.

A standard marking system is used to specify and identify grinding wheels.

The following is the sequence of arrangement:

Abrasive type – Grain size – Grade of bond – Structure – Bond type

51

A

46

H

5

V

8

Position

0

Position

1

Position

2

Position

3

Position

4

Position

5

Position

6

Manufacturer’s Symbol for abrasive (Optional)

Type of abrasive grit size

Grain size

Grade

Structure (Optional)

Type of bond

Manufacturer’s own mark (Optional)

 

The number ‘46’ specifies the average grit size in inch mesh. For a very large size grit, this number may be as small as 6 whereas for a very fine grit the designated number may be as high as 600. 

 

grinding wheel 19 01

  • Abrasive type: ‘A’ for aluminium oxide, ‘C’ for silicon carbide
    • A =  Aluminium oxide
    • B = Cubic boron nitride
    • C = Silicon carbide
    • D = Diamond
  • Grain size: They are indicated by a number ranging from 10 (coarse) up to 600 (very fine)
  • Grade of bond: The grades range from ‘A’ indicating light or ‘soft’ bond to ‘Z’ indicating a firm or ‘hard’ bond
  • Structure: This structure is indicated by a number from 1 to 12. The higher numbers indicate a progressively more open structure
  • Bond type: V – Vitrified, S – Silicate, B – Resinoid, R – Rubber, E – Shellac, O – Oxychloride

For harder materials, the helix angle of the drill is:

  1. Less than 45 degree
  2. Equal to 45 degree
  3. Between 45 to 60 degree
  4. Between 60 to 90 degree

Answer (Detailed Solution Below)

Option 1 : Less than 45 degree

Different Machining Processes Question 12 Detailed Solution

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Explanation:

The helix angle is the angle between the leading edge of the land and the axis of the drill. Sometimes it is also called a spiral angle.

  1. The helix results in a positive cutting rake. This angle is equivalent to the back rake angle of a single-point cutting tool.
  2. The usual range of helix angle used in the drill is 20° to 35°.
  3. Large helix angle 45° to 60° suitable for deep holes and softer work materials.
  4. The small helix angle of less than 45° is suitable for harder and stronger materials.
  5. Zero helix angles are used in spade drills for high production drilling, micro‐drilling, and hard work materials.

Important Points

  1. An increase in helix angle is given for more quick removal of chips but a decrease in helix angle will give greater strength of cutting edges.
  2. The larger the value of helix angle lesser will be the power required in drilling.

Match the Machine Tools (Group A) with the probable Operations (Group B):

Group A

Group B

P: Centre Lathe

1: Slotting

Q: Milling

2: Counter-boring

R: Grinding

3: Knurling

S: Drilling

4: Dressing

  1. P-1, Q-2, R-4, S-3
  2. P-2, Q-1, R-4, S-3
  3. P-3, Q-1, R-4, S-2
  4. P-3, Q-4, R-2, S-1

Answer (Detailed Solution Below)

Option 3 : P-3, Q-1, R-4, S-2

Different Machining Processes Question 13 Detailed Solution

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Explanation:

Centre Lathe → Knurling

Milling → Slotting

Grinding → Dressing

Drilling → Counter-boring

Knurling

Knurling is the operation of producing a straight-lined, diamond-shaped pattern or cross lined pattern on a cylindrical external surface by pressing a tool called knurling tool. Knurling is not a cutting operation but it is a forming operation.

A lathe is used for many operations such as turning, threading, facing, grooving, Knurling, Chamfering, centre drilling

Counter - boring

Counter - boring is an operation of enlarging a hole to a given depth, to house heads of socket heads or cap screws with the help of a counterbore tool.

Dressing:

When the sharpness of grinding wheel becomes dull because of glazing and loading, dulled grains and chips are removed (crushed or fallen) with a proper dressing tool to make sharp cutting edges.

The dressing is the operation of cleaning and restoring the sharpness of the wheel face that has become dull or has lost some of its cutting ability because of loading and glazing.

Slot Milling:

Slot milling is an operation of producing slots like T - slots, plain slots, dovetail slots etc.

The time taken to drill a hole of diameter 25 mm in a 30 mm thick steel plate with a feed of 1 mm/rev and the drill spindle speed being 60 rpm is _________ seconds.

  1. 20
  2. 30
  3. 40
  4. 50

Answer (Detailed Solution Below)

Option 2 : 30

Different Machining Processes Question 14 Detailed Solution

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Concept:

Drilling time can be calculated by;

T=Lf × N

where T = Machining time in min, L = (Approach Length + Thickness of plate) in mm, f = Feed (mm/rev), N = Speed in rpm (revolution per min)

Approach Length=D2 tanθ

Where θ = Half drill bit angle, D = diameter of the hole

The angle of a drill bit is not given in the question hence we will take approach length zero.

∴ L = Thickness of the plate

Calculation:

Given:

Thickness of plate (L) = 30 mm, Feed (f) = 1 mm/rev, Speed (N) = 60 rpm, Hole diameter (d) = 25 mm

T=301×60

T = 0.5 min

T = 0.5 × 60 sec

T = 30 sec

Hence drilling time will be 30 sec.

Important Points

If in the ques it is given that "Neglect approach and over travel" OR "Drill bit angle is not given" then effective length equal thickness of the workpiece.

Grinding wheel with large grain size is used:

  1. for the machining of hard brittle materials.
  2. for small areas of contact.
  3. where a fine surface finish is required.
  4. for the machining of soft ductile materials.

Answer (Detailed Solution Below)

Option 4 : for the machining of soft ductile materials.

Different Machining Processes Question 15 Detailed Solution

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Explanation:

Grinding:

  • Grinding is the process of removing metal by the application of abrasives which are bonded to form a rotating wheel. When the moving abrasive particles contact the workpiece, they act as tiny cutting tools, each particle cutting a tiny chip from the workpiece.
  • It is a common error to believe that grinding abrasive wheels remove material by a rubbing action; actually, the process is as much a cutting action as drilling, milling, and lathe turning.

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Grain size:

  • The grain or grit size of your grinding wheel influences the material removal rate and the surface finish and the grain size varies from 8 to 600 (8 is coarse and 600 is very fine).
  • The grinding wheel grain size controls the possible amount of depth of cut. Bigger grain size protrudes more on the grinding wheel periphery or face resulting in a higher depth of cut and smaller grains protrude less resulting in a lower depth of cut. Hence the size of the chip is fine in the case of smaller grain size wheels.
  • Large grain size grinding wheel is used for ductile materials.
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