1) Which one of the following bonds is most commonly used on grinding wheels?

Shellac

Vitrified

Silicate

Rubber

Correct Answer (B)

2) The cause for glazing of a grinding wheel is ……

A) grain size is too fine

B) wheel is hard.

C) wheel speed is too fast

D) ‘A’ and ‘B’ both

Correct Answer (D)

3) As per Indian Standards the grain size ‘46’ comes under the group

very fine

coarse

medium

fine

Correct Answer (C)

4) A grinding wheel marked with ‘C’ is made with the abrasive

Corundum

Aluminium oxide

Silicon carbide

Diamond

Correct Answer (C)

5) As per Indian Standards the ‘M’ grade of grinding wheel comes under the group

soft

medium

hard

very hard

Correct Answer (B)

6) The symbol conventionally used for resinoid bond is

‘R’

‘B’

‘V’

‘E’

Correct Answer (B)

7) A grinding wheel is marked : 51 A 46 L 5 V —23. Here what does 5 denote?

Kind of abrasive

Kind of bond

Grain size

Structure

Correct Answer (D)

8) Balancing of wheel is done to

make the sides of the wheel parallel

make the outside diameter concentric with the bore

equalize the weight in every position of the wheel

none of the above

Correct Answer (C)

9) Grinding fluids are used to

reduce the friction between the wheel face and the job

wash away chips

prevent loading of wheel

all of the above.

Correct Answer (D)

10) For cylindrical grinding a small diameter work with fairly large wheel, which among the following grades of wheel should be used?

Soft

Medium

Hard

Very soft

Correct Answer (C)

11) Which one of the following is NOT the cause for glazing of wheel?

Hard wheel in place of soft wheel

Feed rate is too fine

Improper dressing of wheel

Dirty coolant

Correct Answer (C)

12) The effect of using a glazed or loaded wheel is

more heat generation

poor surface finish

excessive culling pressure between the wheel face and the work surface

all the above

Correct Answer (D)

13) Which among the following is NOT the cause for loading of grinding wheel?

Feed too fine

Dense structure

Wheel speed more than recommended

Proper grain size and grade of wheel

Correct Answer (C)

14) It is commonly observed that the face of a grinding wheel becomes shiny and smooth or glazed after some use due to one of the following reasons. Choose the correct answer.

Structure of the wheel is too open

Grain size is too coarse

Grade of wheel is too hard

Abrasive of wheel is not suitable for the purpose

Correct Answer (C)

15) What is the cause of a grinding wheel becoming glazed in a grinding machine?

Grinding wheels grade is too soft

Grinding wheel’s grade is too large

Grinding wheel’s speed is too high and work speed is low

Feed and traverse are less

Correct Answer (C)

16) Which one the following features, refers to vitrified bond wheels?

Suitable for wet and dry grinding

Used for longer period due to an elastic structure

Not sensitive to shocks and pressure

Used for longer period due to dense structure

Correct Answer (A)

17) You have to select a grinding wheel with suitable abrasive to grind glass. What is the type of abrasive you ‘will select?

Emery

Silicon carbide

Diamond

Quartz

Correct Answer (C)

18) Dressing and truing of a grinding wheel are

done only for coarse grinding wheels

done with the same equipment

exactly the same operation

only for form grinding wheels

Correct Answer (B)

19) A hardened die block (work) has to be ground. It is required to retain the same hardness even after grinding. If the work is overheated in the grinding process, it may result in work being rejected or scrapped. Probable reason for rejection is that the work surface is

brittle

softened

rough

discoloured

Correct Answer (B)

20) Which one of the following cutting fluids is used during grinding mild steel?

Paraffin

Mineral oil

Non-synthetic cutting oil

Soluble oil

Correct Answer (D)

21) Grinding with a balanced grinding wheel will make it possible to achieve the required

dimensional accuracy with surface finish

Positional tolerance surface finish only

Positional tolerance

Pattern of lay

Correct Answer (A)

22) Snagging is a process used to remove the metal by

filling

hacksawing

chiseling

grinding

Correct Answer (D)

23) Which one of the following materials is used for making a grinding wheel?

Silicon carbide

Granite

Sand

Calcium carbonate

Correct Answer (A)

24) What is the trouble when grinding wheel fails to cut in a grinding machine?

Grinding wheel’s grade is too soft

Grinding wheel is glazed

Grinding wheel is not securely mounted on spindle

Too much feed is given

Correct Answer (B)

25) The depth of infeed per pass in dressing a grinding wheel should be not more than

0.25 mm

0.025 mm

0.0025 mm

0.00025 mm

Correct Answer (B)

26) The grade of a grinding wheel is specified by letters from A to Z. Which are of the followoing refers to the hardest grade?

E

J

P

Y

Correct Answer (D)

27) It is required to finish grind a 050 mm mild steel shaft on a cylindrical grinding machine. What will be the surtace speed if r.p.m?. of the job is 191 ?

20 metres/mm.

25 metres/mm.

30 metres/mm.

35 metres/mm.

Correct Answer (C)

28) Which among the following is the artificial abrasive?

Corrundum

Diamond

Emery

All of the above

Correct Answer (D)

29) By which unit the roughness value is expressed for grinding

µ m

µ in

µ lbs

µ ft

Correct Answer (A)

30) Grain number of grinding wheel is ___ to grain size

Directly proportional

Inversely proportional

Does not depend

None of the above

Correct Answer (B)