FEB 2017

MACHINIST GRINDER
THEORY
SEMESTER-III

1. The silicon carbide abrasive

 is chiefly used for grinding .....

a. Cemented carbide

b. Ceramic

c.  Cast iron

d.  All of these

Answer:- d.  All of these

2. The grinding operation is a ....

a. Shaping operation

b. Forming operation

c. Surface finishing operation

d. Dressing operation

Answer:- c. Surface finishing operation

3. Glazing in grinding wheels

....... cutting capacity.

a. Has no effect on

b. Increase

c. grease

d- None of these

Answer:- c. grease

4. For fast removal of materials

during grinding, a .......... grinding

wheel is used.

a. Coarse grained

b. Fine grained

c.  Medium grained

d. None of these

Answer:- a. Coarse grained

5. In centreless grinding, work

    place centre will be ........

a. Above the line joining the two

     wheel centres

b. Below the line joining the two

     wheel centres

c. On the line joining the two

    wheel centres

d. At the intersection of the line

    joining the wheel centres

Answer:- a. Above the line joining the two

     wheel centres

6. A grinding wheel becomes glazed

(i.e. cutting edge takes a glass-like

appearance) due to ......

a   Wear of bond

b. Breaking of abrasive grains

c. Wear of abrasive grains.

d. Cracks on grinding wheel

Answer:- c. Wear of abrasive grains.

7. A ....... grinding wheel is used to

    grind soft materials.

a. Course grained

b. Medium grained  

c. Fine grained

d. None of these

Answer:- a. Course grained

8. The abrasive recommended for

grinding materials of low tensile

strength is ..............

a. Silicon carbide

b. Aluminium oxide

c.  Sandstone

d. Diamond

Answer:- a. Silicon carbide

9. The process of changing the

shape of grinding wheel as it

becomes worn due to breaking

away of the abrasive and bond.,

is called .........

a. Truing

b. Dressing

c. Facing

d. Clearing

Answer:- a. Truing

10. The actual feed in centerless

grinders is given by (where d = Dia

of regulating wheel, n = Revolutions

per minute. and a = Angle of inclination

of wheel) .............

∏

11. The method of centre less grinding

       used to produce taper is ...........

b   In feed grinding    

b.  Through feed grinding

c   End feed grinding

d    None of these

Answer:- c   End feed grinding

12. Thread grinding requires work

        speed from ......

a. 1 to 3 m/mm

b. 5 to 10 m/min

c. 10 to 14 m/min
d. 14 to 20 m/min

Answer:- a. 1 to 3 m/mm

13. The grinding wheel speed

(surface speed in m/min) usually

varies from-

a. 500 to 1000
b. 1000 to 1500

c. 1500 to 2000
d. 2000 to 2500

Answer:- c. 1500 to 2000

14. The in-feed grinding is used to-
a. Produce tapers

b. Grind shoulders and formed surfaces

c. Grind long, slender shafts or bars

d. All of these

Answer:- b. Grind shoulders and formed surfaces

15. Fixtures are used ......

a. For holding and guiding the tool

    in drilling, reaming or lapping operations

b. For holding the work in milling,

      grinding. planing or turning operations

c. I o check the accuracy of work piece

d. None of the above           

Answer:- b. For holding the work in milling,

      grinding. planing or turning operations

16. The work or surface speed for

    cylindrical grinding varies from ......

a. 5 to 30 m/min

b. 10 to 20 m/min

c. 20 to 30 m/min

d. 40 to 60 m/min

Answer:- b. 10 to 20 m/min

17. The performance of grinding wheel is

evaluated in terms of grinding ratio

(G) which is given by the ratio of .........

a. The volume of material required to the

     volume of wheel wear
b. The volume of wheel wear to the volume

     of material required

c. Both (a) & (b)
d. None of the above

Answer:- a. The volume of material required to the

     volume of wheel wear

18. In order to grind soft material-

a. coarse grained grinding wheel is used

b. Fine grained grinding wheel is used

c Medium grained grinding wheel is used

d. None of above

Answer:- a. coarse grained grinding wheel is used

19. When the finishing is more

 important than the dimension then ............

a. Honing operation is carried out for finishing

b. Lapping operation is carried out for finishing

c. Grinding operation is carried out for finishing

d. All of the above

Answer:- b. Lapping operation is carried out for finishing

20. A device, in which a component is

held and located for a specific operation

and bushes are integrated that guide the

tool, is called as-

a. Jig          

b. Fixture

c. Both (a) and (b)

d. None of these

Answer:- a. Jig          

21. The device which place the work piece

 in the same position, in jig and fixture,

cycle after cycle is called as-

a. Placing device

b. Fixing device

c.  Locating device

d. Positioning device

Answer:- c.  Locating device

22. V-blocks (Vee locators) are used

for clamping as well as locating when

faces are inclined upto .........

a, 30°

b. 12°

c. 9°

d. 3°

Answer:- b. 12°

23. What kind of material can

you grind with aluminum oxide

grinding wheels?

a. Only aluminum.

b. Any type of metal.

c. Any metal with a yellow, gold

    or amber hue.

d. Ferrous or iron-based materials,

    like iron or steel.

Answer:- d. Ferrous or iron-based materials,

    like iron or steel.

24. How much of a gap should there

      be between the work rest and the

      face of the grinding wheel?

a. 1/8" or less

b. Not less than 1/8"

c. 1/4" 

d. P

Answer:- a. 1/8" or less

25. The wheel hole diameter and the

grinder arbor size are not the same.

What can you do to make the wheel

workable?

a. The wheel is not compatible with

     the grinder. Do not install it.

b. Go ahead and install it, even if you

  have to force the wheel onto the spindle.

c. Screw on the wheel nut especially tight

d. Both(b)&(c)

Answer:- a. The wheel is not compatible with

     the grinder. Do not install it.

26. The branch of science dealing with

wear, tear and lubrications is called-

a. Ergonomics

b. Tribology

c.  Mechatronics

d. None of these

Answer:- d. None of these

27. What is the cause of a grinding

      wheel becoming glazed in a

       grinding machine?

a. Grinding wheel's grade is too soft

b. Grinding wheel's grade is too large

c. Feed and traverse are less

d. Grinding wheel's speed is too high

     and work speed is low

Answer:- d. Grinding wheel's speed is too high

     and work speed is low

28. You have to select a grinding wheel

      with suitable abrasive to grind glass.

      What is the type of abrasive you

      will select?

a. Diamond

b- Emery

c. Quartz

d. Silicon carbide

Answer:- a. Diamond

29. Which one of the following features,

       refers to vitrified bond wheels?

a. Used for longer period due to

     dense structure

b. Used for longer period due to an

     elastic structure

c. Not sensitive to shocks and pressure

d. Suitable for wet and dry grinding

Answer:- b. Used for longer period due to an

     elastic structure

30. For cylindrical grinding a small

      diameter work with fairly large

      wheel, which among the following

       grades of wheel should be used?

a. Soft

b. Medium

c Hard

d   Very soft

Answer:- c.  Hard

31. As per Indian Standards the 'K' grade

      of grinding wheel comes under the

      group .......

a.  Soft

b. Medium

c. Hard

d   Very hard

Answer:- b. Medium

32. What will happen if the job is loosely

       fitted between centres in cylindrical

    grinding?

a. The job will be out of round

b. The job will be oversized

c.  The job will be thrown out

d. The job will not rotate

Answer:- a. The job will be out of round

33. Which one of the following cutting

fluids is used during grinding mild steel?

a. Mineral oil

b. Non-synthetic cutting oil

c. Soluble oil

d.  Paraffin

Answer:- c. Soluble oil

34. Grinding fluids are used to-

a. Reduce the friction between the

     wheel face and the job

b. Wash away chips

c. Prevent loading of wheel

d. All of the above

Answer:- d. All of the above

35. The symbol conventionally used

      for resinoid bond

a. V

b. R

c. B

d. E

Answer:- c. B

36. per Indian standards the M grade

    of grinding wheel come under the

    group ........
a. Soft

b. Medium

c. Hard

d.  Very hard

Answer:- b. Medium

37. Which one of the following instruments

 is used to check the concentricity

of the outside diameter?

a. Vernier caliper

b. Outside micrometer

c. Dial test indicator

d. Dial caliper

Answer:- c. Dial test indicator

38. To convert the linear motion of the

plunger of a dial test indicator to the

 rotary motion of the pointer, which

one of the following mechanisms is used

mechanism

a. Quick return mechanism 
b. Rack and pinion mechanism

c Screw thread mechanism

d. Hydraulic mechanism

Answer:- b. Rack and pinion mechanism

39. The principle of universal bevel

protractor is similar that of ......

a. Verniar bevel protractor

b. Depth micrometer

c. Dial test indicator
d. Fixed gauge

Answer:- a. Verniar bevel protractor

40. A flange micrometer is used to

measure .........

a. Outside diameter of a gear

b. Chordl thickness of gear

c. Addendum of the gear
d. None of these

Answer:- b. Chordl thickness of gear

41. While laying out. the vernier

height gauge must be used on the ......

a. Surface plate

b. Vee block

c. Machine bed 

d. Any flat surface

Answer:- a. Surface plate

42. On which part of the vernier

height gauge, are the main scale

divisions graduated?

a. Vernier plate

b. Beam

c. Fine adjusting
d. Base

Answer:- b. Beam

43. Rotation to the work piece in

plain cylindrical centre type

grinder is given by-

a. Live centre

b. Steady centre

c. Driving plate

d. None of these

Answer:- c. Driving plate

44. To reverse the direction of sliding

table in a cylindrical centre type

grinder, ....... are.provided in the machine.

a. Spindle

b. Trip dogs

c. Bonds in the wheel
d. None of these

Answer:- b. Trip dogs

45. In centre less grinding, the work

 piece is advanced by-

a. Force exerted by the regulating wheel

b. Manually

c. Automotive drive
d. None of these

Answer:- a. Force exerted by the regulating wheel

46. How will you ensure the

correctness of internal radius?
a. By radius gauge

b. By seating a round ball bearing

c.  By grinding an internal radius

     tool equal to the radius of job to

     do the operation

d. By template

Answer:- c.  By grinding an internal radius

     tool equal to the radius of job to

     do the operation

47. A rough turning tool is ground by

hand on a pedestal grinder .

A after grinding

it is observed that the grounded

of the tool are concaved.

Which of the following

statements is the cause for

this defect?

a.  Tool rest not set to the required angle

b.  Tool held in one position only

      against the wheel

c. Surface speed of the grinding wheel is

    not as specified

d. The grinding is carried out on a

     peripheral grinding wheel

Answer:- d. The grinding is carried out on a

     peripheral grinding wheel