EDM Material Removal MCQs : This section focuses on the "EDM Material Removal". These Multiple Choice Questions (MCQs) should be practiced to improve the EDM Material Removal skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Question 1
After the explosion is over, how is the debris carried away?
A. Evaporation
B. Fresh dielectric
C. Old dielectric
D. All of the mentioned
Question 2
Amount of material removed from anode and cathode depend on which of the following?
A. Electrons
B. Positive ions
C. Electrons & Positive ions
D. None of the mentioned
Question 3
At the end of pulse, super-heated metal evaporates _______________
A. Explosively
B. Normally
C. Periodically
D. Occasionally
Question 4
Between what values mentioned below, do the discharges and sparks usually vary?
A. 1 and 10,000
B. 500 and 500,000
C. 500,000 and 1,000,000
D. None of the mentioned
Question 5
Based on the electrode gap, which of the following electric pulses are generated?
A. Open Circuit pulses
B. Sparks
C. Arcs
D. All of the mentioned
Question 6
Open gap voltages contribute to how much amount of material removal?
A. 20 %
B. 50 %
C. 70 %
D. No contribution
Question 7
The layer formed when unexpelled molten metal solidifies is known as _______________
A. Reabsorbed layer
B. Recast layer
C. Unevaporated layer
D. Condensed layer
Question 8
What are the magnitude of voltages used in Electro discharge machining?
A. 1 to 20 V
B. 20 to 120 V
C. 120 to 220 V
D. 220 to 320 V
Question 9
What are the values of gaps between the electrodes in EDM?
A. 0.001 – 0.05 mm
B. 0.01 – 0.5 mm
C. 0.1 – 5 mm
D. 1 – 15 mm
Question 10
What are the values of pressure of the plasma in EDM?
A. Up to 2 atm
B. Up to 20 atm
C. Up to 200 atm
D. Up to 2000 atm
Question 11
What are the values of temperature that are obtained while machining using EDM?
A. 2000 to 3000ᵒC
B. 4000 to 6000ᵒC
C. 8000 to 12000ᵒC
D. 15000 to 20000ᵒC
Question 12
What happens when the electron current predominates in the discharge?
A. More anodic removal
B. More cathodic removal
C. Remains same
D. All of the mentioned
Question 13
What is the duration of sparks that are produced in Electro discharge machining?
A. 0.001 – 1 µs
B. 0.1 – 2000 µs
C. 0.2 – 100 ms
D. 100 – 2000 ms
Question 14
What is the radius of channel, when electrical breakdown occur?
A. 4 µm
B. 6 µm
C. 8 µm
D. 10 µm
Question 15
What is the value of gap maintained between the electrodes when we use servo mechanism?
A. 10 – 100 µm
B. 100 – 200 µm
C. 200 – 500 µm
D. 500 – 1000 µm
Question 16
What is the value of order of frequency applied between the two electrodes in EDM?
A. 1 kHz
B. 3 kHz
C. 5 kHz
D. 7 kHz
Question 17
What range of heat fluxes are obtained while machining using EDM?
A. 1017 W/m2
B. 1019 W/m2
C. 1024 W/m2
D. 1027 W/m2
Question 18
When the electrode gap is too small or electrodes are in contact, how much material is removed?
A. 10%
B. 20%
C. 30%
D. No material removed
Question 19
Which components mentioned below are affected due to arcs?
A. Work piece
B. Tool
C. Work piece & Tool
D. None of the mentioned
Question 20
Which of the following pulses contribute to the desired material removal in EDM?
A. Open circuit pulses
B. Short circuits
C. Arcs
D. Sparks