250+ TOP MCQs on Electric Discharge Machining and Answers

Manufacturing Engineering Multiple Choice Questions on “Electric Discharge Machining”.

1. Which of the following machine uses non conventional machining technique for metal removal?
a) Grinding machine
b) Milling machine
c) Electric discharge machine
d) None of the mentioned
Answer: c
Clarification: Electronic discharge machine is a non conventional machining technique for metal removal.

2. Which of the following material cannot be machined using electronic discharge machine?
a) Iron
b) Aluminum
c) Copper
d) Wood
Answer: d
Clarification: Wood is a bad conductor of electricity and hence cannot be machined using electronic discharge machine.

3. Which of the following material can be machined using electronic discharge machine?
a) Iron
b) Rubber
c) Plastic
d) Wood
Answer: a
Clarification: Iron is a good conductor of electricity and hence can be machined using electronic discharge machine.

4. Which of the following EDM machine is used for cutting shapes cut out of a flat sheet or plate of metal?
a) Wire EDM
b) Sinker EDM
c) Wire and Sinker EDM both
d) None of the mentioned
Answer: a
Clarification: Wire EDM used for cutting shapes cut out of flat sheet or plate of metal. It is an unconventional process of machining.

5. Which of the following EDM machine is used for die cast tooling?
a) Wire EDM
b) Sinker EDM
c) Wire and Sinker EDM both
d) None of the mentioned
Answer: b
Clarification: Sinker EDM is used for die cast tooling. It is an unconventional process of machining.

6. Dielectric medium in EDM is used for
a) Flushing away the debris
b) To make the medium conducting
c) To decrease the material removal rate
d) None of the mentioned
Answer: a
Clarification: Dielectric in EDM is used for flushing away the debris generated during the process of machining, which may slow down the material removal rate if not removed instantly.

7. Material removal rate in EDM increases with
a) Increase in melting point of work piece
b) Increase in Current
c) Decrease in current
d) None of the mentioned
Answer: b
Clarification: MRR is directly proportional to the current.

8. Material removal rate in EDM increases with
a) Increase in melting point of work piece
b) Decrease in Current
c) Decrease in melting point of work piece
d) None of the mentioned
Answer: c
Clarification: MRR is inversely proportional to a melting point of work piece.

9. For maximum power delivery using resistance capacitance relaxation circuit in EDM, discharge voltage should ___ % of the supply voltage?
a) 80
b) 23
c) 65
d) 72
Answer: d
Clarification: Find optimum value using L-C circuits.

10. In an EDM machine, metal removal rate is 1.937 cubic mm / min. If total amount of material to removed is 600 cubic mm. Time required in min will be
a) 100
b) 200
c) 309
d) 402
Answer: c
Clarification: Time required= (Total material to be removed/material removal rate).