Ohio CNC Operator Level 2 Practice
d d d d d
Exam Questions And Correct Answers (Ver
d d d d d
ified Answers) Plus Rationales 2026|2027
d d d d d
Q&A | Instant Download Pdf
d d d d
1. What does G00 code typically command on a CNC machine?
d d d d d d d d d d
A) Feed at programmed feed rate
d d d d
B) Rapid positioning d
C) Circular interpolation d
D) Thread cutting d
Rationale: G00 is used for rapid, non- d d d d d d
cutting moves to position the tool quickly.
d d d d d d
2. Which coordinate system is referenced to the machine’s physical zero
d d d d d d d d d d
point?
A) Work offset d
B) Tool offset d
C) Machine coordinate system (MCS) d d d
D) Local coordinate system d d
, Rationale: MCS is fixed to the machine and used as a reference for all p
d d d d d d d d d d d d d d
ositions.
3. What is the primary function of G01 code?
d d d d d d d
A) Rapid traverse d
B) Drill cycle d
C) Linear interpolation at a programmed feed rate
d d d d d d
D) Peck drilling d
Rationale: G01 moves the tool in a straight line at a controlled feed rate
d d d d d d d d d d d d d
dfor cutting.
d
4. Which coolant type is typically used for aluminum machining?
d d d d d d d d
A) Water-soluble oil d
B) Straight oil d
C) Synthetic oil d
D) Water-based coolant d
Rationale: Water- d
based coolant provides good cooling and chip evacuation for aluminum.
d d d d d d d d d
5. What does the “tool offset” compensate for?
d d d d d d
A) Material hardness d
B) Tool length and diameter variations
d d d d
C) Machine vibration d
D) Workholding misalignment d
Rationale: Tool offsets ensure the machine compensates for actual tool
d d d d d d d d d
dsize and length.
d d
,6. Which factor has the greatest effect on tool life?
d d d d d d d d
A) Machine weight d
B) Cutting speed d
C) Workpiece color d
D) Coolant color d
Rationale: Cutting speed directly affects heat generation and tool we
d d d d d d d d d
ar.
7. What does the G02 command perform?
d d d d d
A) Linear movement d
B) Clockwise circular interpolation d d
C) Counterclockwise circular interpolation d d
D) Drill cycle d
Rationale: G02 moves the tool along a clockwise arc in the XY plane.
d d d d d d d d d d d d
8. Which type of CNC machine is primarily used for turning?
d d d d d d d d d
A) Milling machine d
B) Drilling machine d
C) Lathe
D) EDM machine d
Rationale: A lathe rotates the workpiece and uses a stationary cutting
d d d d d d d d d d
tool for turning operations.
d d d d
9. When programming a part in inches, what code is used?
d d d d d d d d d
A) G21
B) G20
, C) G90
D) G91
Rationale: G20 sets the CNC to inch mode; G21 sets metric mode.
d d d d d d d d d d d
10. What does the “fixture offset” compensate for?
d d d d d d
A) Tool wear
d
B) Machine calibration d
C) Workpiece location on the table d d d d
D) Coolant flow d
Rationale: Fixture offsets adjust the coordinate system to match the physi
d d d d d d d d d d
cal placement of the workpiece.
d d d d
11. What is the purpose of peck drilling cycles?
d d d d d d d
A) Increase spindle speed d d
B) Break chips and reduce heat during deep hole drilling
d d d d d d d d
C) Decrease tool diameter d d
D) Polish the hole surface
d d d
Rationale: Peck drilling retracts the drill periodically to prevent chip clogg
d d d d d d d d d d
ing and overheating.
d d
12. Which motion mode is G03 used for?
d d d d d d
A) Rapid traversed
B) Linear feed d
C) Counterclockwise circular interpolation d d
D) Drilling cycle d
Rationale: G03 performs CCW arcs in the XY plane.
d d d d d d d d
d d d d d
Exam Questions And Correct Answers (Ver
d d d d d
ified Answers) Plus Rationales 2026|2027
d d d d d
Q&A | Instant Download Pdf
d d d d
1. What does G00 code typically command on a CNC machine?
d d d d d d d d d d
A) Feed at programmed feed rate
d d d d
B) Rapid positioning d
C) Circular interpolation d
D) Thread cutting d
Rationale: G00 is used for rapid, non- d d d d d d
cutting moves to position the tool quickly.
d d d d d d
2. Which coordinate system is referenced to the machine’s physical zero
d d d d d d d d d d
point?
A) Work offset d
B) Tool offset d
C) Machine coordinate system (MCS) d d d
D) Local coordinate system d d
, Rationale: MCS is fixed to the machine and used as a reference for all p
d d d d d d d d d d d d d d
ositions.
3. What is the primary function of G01 code?
d d d d d d d
A) Rapid traverse d
B) Drill cycle d
C) Linear interpolation at a programmed feed rate
d d d d d d
D) Peck drilling d
Rationale: G01 moves the tool in a straight line at a controlled feed rate
d d d d d d d d d d d d d
dfor cutting.
d
4. Which coolant type is typically used for aluminum machining?
d d d d d d d d
A) Water-soluble oil d
B) Straight oil d
C) Synthetic oil d
D) Water-based coolant d
Rationale: Water- d
based coolant provides good cooling and chip evacuation for aluminum.
d d d d d d d d d
5. What does the “tool offset” compensate for?
d d d d d d
A) Material hardness d
B) Tool length and diameter variations
d d d d
C) Machine vibration d
D) Workholding misalignment d
Rationale: Tool offsets ensure the machine compensates for actual tool
d d d d d d d d d
dsize and length.
d d
,6. Which factor has the greatest effect on tool life?
d d d d d d d d
A) Machine weight d
B) Cutting speed d
C) Workpiece color d
D) Coolant color d
Rationale: Cutting speed directly affects heat generation and tool we
d d d d d d d d d
ar.
7. What does the G02 command perform?
d d d d d
A) Linear movement d
B) Clockwise circular interpolation d d
C) Counterclockwise circular interpolation d d
D) Drill cycle d
Rationale: G02 moves the tool along a clockwise arc in the XY plane.
d d d d d d d d d d d d
8. Which type of CNC machine is primarily used for turning?
d d d d d d d d d
A) Milling machine d
B) Drilling machine d
C) Lathe
D) EDM machine d
Rationale: A lathe rotates the workpiece and uses a stationary cutting
d d d d d d d d d d
tool for turning operations.
d d d d
9. When programming a part in inches, what code is used?
d d d d d d d d d
A) G21
B) G20
, C) G90
D) G91
Rationale: G20 sets the CNC to inch mode; G21 sets metric mode.
d d d d d d d d d d d
10. What does the “fixture offset” compensate for?
d d d d d d
A) Tool wear
d
B) Machine calibration d
C) Workpiece location on the table d d d d
D) Coolant flow d
Rationale: Fixture offsets adjust the coordinate system to match the physi
d d d d d d d d d d
cal placement of the workpiece.
d d d d
11. What is the purpose of peck drilling cycles?
d d d d d d d
A) Increase spindle speed d d
B) Break chips and reduce heat during deep hole drilling
d d d d d d d d
C) Decrease tool diameter d d
D) Polish the hole surface
d d d
Rationale: Peck drilling retracts the drill periodically to prevent chip clogg
d d d d d d d d d d
ing and overheating.
d d
12. Which motion mode is G03 used for?
d d d d d d
A) Rapid traversed
B) Linear feed d
C) Counterclockwise circular interpolation d d
D) Drilling cycle d
Rationale: G03 performs CCW arcs in the XY plane.
d d d d d d d d
