1. Mechanism of material removal in Electron Beam Machining is due to

a) Mechanical erosion due to impact of high of energy electrons

b) Chemical etching by the high energy electron

c) Sputtering due to high energy electrons

d) Melting and vaporisation due to thermal effect of impingement of high energy electron

2. Mechanism of material removal in Laser Beam Machining is due to

a) Mechanical erosion due to impact of high of energy photons

b) Electro-chemical etching

c) Melting and vaporisation due to thermal effect of impingement of high energy laser

beam

d) Fatigue failure

3. Generally Electron Beam Gun is operated at

a) Atmospheric pressure

b) At 1.2 bar pressure above atmosphere

c) At 10 – 100 mTorr pressure

d) At 0.01 – 0.001 mTorr pressure

4. Laser Beam is produced due to

a) Spontaneous emission

b) Stimulated emission followed by spontaneous emission

c) Spontaneous emission followed by Spontaneous absorption

d) Spontaneous absorption leading to “population inversion” and followed by stimulated

emission

5. For ECM of steel which is used as the electrolyte

(a) kerosene

(b) NaCl

(c) Deionised water

(d) HNO3

6. MRR in ECM depends on

(a) Hardness of work material

(b) atomic weight of work material

(c) thermal conductivity of work material

(d) ductility of work material

7. ECM cannot be undertaken for

(a) steel

(b) Nickel based superalloy

(c) Al2O

3

(d) Titanium alloy

8. Commercial ECM is carried out at a combination of

(a) low voltage high current

(b) low current low voltage

(c) high current high voltage

(d) low current low voltage

9. Which of the following material cannot be machined by EDM

(a) steel

(b) WC

(c) Titanium

(d) Glass

10. Which of the following is used as dielectric medium in EDM

(a) tap water

(b) kerosene

(c) NaCL solution

(d) KOH solution

11. Tool should not have

(a) low thermal conductivity

(b) high machinability

(c) high melting point

(d) high specific heat

12. AJM nozzles are made of

(a) low carbon steel

(b) HSS

(c) WC

(d) Stainless steel

13. Material removal in AJM of glass is around

(a) 0.1 mm3

/min

(b) 15 mm3

/min

(c) 15 mm3

/s

(d) 1500 mm3

/min

14. Material removal takes place in AJM due to

(a) electrochemical action

(b) mechanical impact

(c) fatigue failure of the material

(d) sparking on impact

15. Which of the following material is not generally machined by USM?

(i) Copper

(ii) Glass

(iii) Silicon

(iv) Germanium

16. Tool in USM is generally made of

(i) Glass

(ii) Ceramic

(iii) Carbides

(iv) Steel

17. Increasing volume concentration of abrasive in slurry would affect MRR in the

following manner

(i) increase MRR

(ii) decrease MRR

(iii) would not change MRR

(iv) initially decrease and then increase MRR

18. USM can be classified as the following type of non-traditional machining process

(i) electrical

(ii) optical

(iii) mechanical

(iv) chemical

19. LBM system can effectively machine

(i) refractory materials, (ii) tungsten carbide, (iii) copper, (iv) M.S.

20. The efficiency of LBM system is about

(i) 3 to 5 %, (ii) 13 to 15 %, (iii) 0.3 to 0.5 %, (iv) 30 to 50 %.

21. While drilling deep hole by LBM process, the hole produced is

(i) straight sided, (ii) converging type, (iii) diverging type, (iv) none of these.

22. The suitable process(es) for machining a 5 mm deep blind, complex contoured cavity

in M. S. sheet of 20 mm thickness is (are)

(i) LBM, (ii) EDM, (iii) ECM, (iv) AFM.

23. Commonly used process(es) for machining of cooling holes in a turbine blade is (are)

(i) USM, (ii) AWJM, (iii) LBM, (iv) EBM, (v) EDM, (vi) ECM.

24. Surface damage to the machined component is significant in case of

(1) EDM, (2) ECM, (3) Grinding, (4) PAM.

25. During calculation of MRR in EDM, supply voltage was used as 60V in place of the

actual supply voltage as 40V. What is the ratio of actual and calculated MRR? Assume

that the condition for maximum power delivery to the discharging circuit is satisfied.

(1) 1.5, (2) 0.44, (3) 2.25, (4) none.

26. The nature of current used for EDM is

(1) AC, (2) DC, (3) pulsed AC, (4) Pulsed DC.

27. Stratified wires are used so that they can

(1) withstand more forces, (2) carry more heat energy, (3) both of these, (4) none of

these.

28. For maximum power delivery through the R-C circuit for EDM, the ratio of the

breakdown voltage to supply voltage is equal to :

(1) 0.72, (2) 1.0, (3) 0.75, (4) 0.65.

29. Feed to the electrode in EDM ensures

(1) constant velocity of dielectric flow in the IEG, (2) constant IEG, (3) constant

current density, (4) none of these.

30. The surface roughness in EDM with the increase in breakdown voltage

(1) increases, (2) decreases, (3) remains unchanged.

31. A Servomechanism operates when there is

(1) short circuit, (2) high IEG, (3) low IEG, (4) none of these.

32. Poor flushing during EDM results in

(1) low MRR, (2) short circuit, (3) both, (4) none

(2)

33. If the flushing system of an EDM m/c is efficient the machining cycle time will be

(1) longer, (2) shorter, (3) no effect, (4) no definite trend.

34. Wear of tool during EDM process would result in

(1) deeper hole, (2) lesser diameter hole, (3) both.

35. During EDM with a relaxation generator the charged voltage of the condenser is

increased from V1 to V2 (V2 = 4V1). What will be surface roughness at V2 if its value at V1

is equal to Ra1.

(1) 2 Ra1, (2) 2.5 Ra1, (3) 4 Ra1, (4) 0.25 Ra1.

36. Which process would you recommend to make cooling holes (diam = 0.5 mm, and

depth to diameter ratio may be as high as 75) in a turbine blade.

(1) EDM, (2) AJM, (3) USM, (4) PAM.

37. Mechanism of material removal in Electron Beam Machining is due to

a) Mechanical erosion due to impact of high of energy electrons

b) Chemical etching by the high energy electron

c) Sputtering due to high energy electrons

d) Melting and vaporisation due to thermal effect of impingement of high energy

electron

38. Mechanism of material removal in Laser Beam Machining is due to

a) Mechanical erosion due to impact of high of energy photons

b) Electro-chemical etching

c) Melting and vaporisation due to thermal effect of impingement of high energy laser

beam

d) Fatigue failure

39. Generally Electron Beam Gun is operated at

a) Atmospheric pressure

b) At 1.2 bar pressure above atmosphere

c) At 10 – 100 mTorr pressure

d) At 0.01 – 0.001 mTorr pressure

40. Laser Beam is produced due to

a) Spontaneous emission

b) Stimulated emission followed by spontaneous emission

c) Spontaneous emission followed by Spontaneous absorption

d) Spontaneous absorption leading to “population inversion” and followed by

stimulated emission

INTERVIEW

QUESTIONS

Two Marks

&

Big Questions

Anna

University Questions

Unit – 1

Unit – 2

Unit – 3

Unit – 4

Unit – 5