Thursday, September 10, 2015

MCQ on Mechanical Energy Based Unconventional Machining Process


MCQ on Mechanical Energy Based Unconventional Machining Process

1.In abrasive jet machining, as the distance between the nozzle tip and the work surface increases, the material removal rate

a)increases continuously

b) decreases continuously

c) decreases, becomes stable and then increases

d) increases, becomes stable and then decreases

 

2.The size of abrasive grains in abrasive jet machining ranges from

a) 1 to 10 microns

b) 10 to 50 microns

c) 50 to 100 microns

d) 100 to 500 microns

 

3.The vibrating frequency used for the tool in Ultrasonic machining is of the order of

a) 10,000 oscillations per second

b) 35,000 oscillations per second

c) 35,000 oscillations per second

d) 45,000 oscillations per second

 

4.In Ultrasonic machining, the material is removed by

a) anodic dissolution

b) thermal melting

c) abrasive action

d) electrochemical oxidation

 

5.Ultrasonic machining can machine both metallic and non-metallic surfaces

a) True

b) False

 

6.Which of the following machining process(es) use mechanical energy as the principal energy source ?

a) conventional milling

b) water jet cutting

c) wire cut EDM

d) abrasive jet machining

 

 

7.Abrasives contained in a slurry are driven at a high velocity against the work by a tool vibrating at low amplitude and high frequency.This is the metal removing mechanism for__________________

a) USM

b) LBM

c) WJM

d) AJM

 

8.In USM, the amplitude of  vibrating tool is,

a) 10 - 50 micro meter

b) 500 - 5000 micro meter

c) 20 - 20000 micro meter

 

 

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

a) Copper

b) Glass

c) Silicon

d) Germanium

 

10.Tool in USM is generally made of

a) Glass

b) Ceramic

c) Carbides

d) Steel

 

11.Increasing volume concentration of abrasive in slurry (in USM process)  would affect MRR in the following manner

a) increase MRR

b) decrease MRR

c) would not change MRR

d) initially decrease and then increase MRR

 

 

12.In water jet cutting and abrasive water jet cutting, the separation between the nozzle opening and the work surface is called which one of the following

a) Gap

b) gap size

c) orifice

d stand-off distance

 

13.In abrasive water jet cutting, the abrasive particles are added to the water stream

after it exits the nozzle

a) before it enters the pumping unit

b) just before it enters the nozzle

c) while it is in the nozzle

 

14.AJM nozzles are made of

a) low carbon steel

b) HSS

c) WC

d) Stainless steel

 

15.Material removal takes place in AJM due to

a) electrochemical action

b) fatigue failure of the material

c) sparking on impact

d) mechanical impact

 

16.As the stand off distance increases, the depth of penetration in AJM

a) Increases

b) decreases

c) does not change

d) initially increases and then remains steady

 

 

17.Abrasive slurry is used in the following type of machining process.

a) Ultrasonic machining

b) Conventional milling

c) Wire cut EDM

d) Laser beam machining

 

18.The following principle is used for converting electrical energy into mechanical energy in USM

a) Faraday's law

b) Stefan's law

c) Piezoelectric effect

d) Thomson's law

 

19.The following device is used for converting electrical impulses into mechanical vibration in USM

a) Transducer

b) oscillator

c) tank

d) pump

 

20.In AJM, removal of metal takes place by bombardment of fine grained particle.

a) with air at high velocity

b) with water at high velocity

c) with kerosene at high velocity

d) at controlled rate in brine

 

21.In WJM, removal of metal takes place by bombardment of fine grained particle.

a) with air at high velocity

b) with water at high velocity

c) with kerosene at high velocity

d) at controlled rate in brine

 

22.WJM cannot be used to machine

a) frozen food

b) plywood

c) leather
d) steel plates

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