Question:

What happens when the current density is low in ECM?

A.

pitting occurs

B.

etching occurs

C.

pitting & etching occurs

D.

none of the mentioned

Answer» c. pitting & etching occurs

Question:

Selection of electrolyte does not depend on which of the following factors?

A.

work piece material

B.

dimensional tolerance

C.

heat affected zones

D.

machining productivity

Answer» c. heat affected zones

Question:

Apparent current efficiency is due to which of the following factors?

A.

choice of wrong valence

B.

passivation of anodic surface

C.

gas evolution at anode

D.

all of the mentioned

Answer» d. all of the mentioned

Question:

What must be the value of the pressure of electrolytic solution used in ECM?

A.

1 to 10 kpa

B.

10 to 80 kpa

C.

100 to 200 kpa

D.

300 to 400 kpa

Answer» c. 100 to 200 kpa

Question:

What happens to the product cycle time, if the machining performance is improved?

A.

increases

B.

decreases

C.

remains same

D.

none of the mentioned

Answer» b. decreases

Question:

State whether the following statement is true or false about electrolyte in ECM. “Machinability in ECM is enhanced, when electrolyte is heated.”

A.

true

B.

false

Answer» a. true

Question:

In Electrochemical machining, larger grain size causes which type of finish?

A.

smoother

B.

rougher

C.

finer

D.

all of the mentioned

Answer» b. rougher

Question:

Fine dimensional control can be obtained if throwing power of electrolyte is

A.

low

B.

medium

C.

high

D.

very high

Answer» a. low

Question:

ECM is used to                    the sharp edges produced after rough cuts.

A.

enhance

B.

dull

C.

improve

D.

none of the mentioned

Answer» b. dull

Question:

What must be the value of electrolytic temperature in ECM?

A.

2 to 14oc

B.

22 to 45oc

C.

46 to 57oc

D.

62 to 76oc

Answer» b. 22 to 45oc