Ohio CNC Operator Level 1 Practice
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales
|2026 Q&A | Instant Download Pdf
1. What does CNC stand for?
A. Computer Numerical Control
B. Computerized Numerical Control
C. Calculated Numerical Control
D. Controlled Numerical Calibration
Rationale: CNC machines are automated milling or turning machines
controlled by a computer using numerical data.
2. Which axis typically represents left-right movement on a CNC
machine?
A. Y-axis
B. Z-axis
, C. X-axis
D. W-axis
Rationale: On CNC machines, the X-axis usually represents horizontal
movement left and right.
3. The purpose of a coolant in CNC machining is to:
A. Increase friction
B. Reduce heat and remove chips
C. Harden the cutting tool
D. Lubricate the motor
Rationale: Coolant prevents overheating of both the tool and workpiece
and helps flush away chips.
4. What is the standard unit for spindle speed in CNC machines?
A. RPM
B. Revolutions per minute
C. Hz
D. M/min
Rationale: Spindle speed refers to how many revolutions per minute the
spindle makes.
5. Which G-code is used to move the tool to a specific coordinate at a
controlled feed rate?
A. G00
B. G01
, C. G02
D. G03
Rationale: G01 is a linear interpolation code for moving at a controlled
feed rate.
6. G02 is used for:
A. Linear movement
B. Clockwise circular interpolation
C. Counterclockwise circular interpolation
D. Rapid positioning
Rationale: G02 commands a clockwise arc movement in CNC machining.
7. Which part of the CNC machine holds the cutting tool?
A. Chuck
B. Spindle
C. Bed
D. Tailstock
Rationale: The spindle rotates and holds the cutting tool in place.
8. The difference between G00 and G01 is:
A. G00 is linear, G01 is circular
B. G00 is rapid movement, G01 is controlled feed
C. G00 rotates clockwise, G01 counterclockwise
D. There is no difference
, Rationale: G00 moves the tool rapidly without concern for cutting, while
G01 moves at a feed rate suitable for cutting.
9. What is the purpose of a tool offset?
A. Speed up spindle rotation
B. Adjust for tool length and diameter
C. Reduce vibration
D. Change coolant flow
Rationale: Tool offsets allow precise compensation for the tool’s actual
physical dimensions.
10. Which device measures the actual position of a CNC axis?
A. Encoder
B. Stepper
C. Servo motor
D. Linear scale
Rationale: Linear scales provide feedback on the exact position of CNC axes
for precision.
11. What does “H” represent in a tool offset?
A. Diameter
B. Height (length)
C. Helix angle
D. Hardness
Rationale: H-codes are used in tool offset tables to specify the tool length.
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales
|2026 Q&A | Instant Download Pdf
1. What does CNC stand for?
A. Computer Numerical Control
B. Computerized Numerical Control
C. Calculated Numerical Control
D. Controlled Numerical Calibration
Rationale: CNC machines are automated milling or turning machines
controlled by a computer using numerical data.
2. Which axis typically represents left-right movement on a CNC
machine?
A. Y-axis
B. Z-axis
, C. X-axis
D. W-axis
Rationale: On CNC machines, the X-axis usually represents horizontal
movement left and right.
3. The purpose of a coolant in CNC machining is to:
A. Increase friction
B. Reduce heat and remove chips
C. Harden the cutting tool
D. Lubricate the motor
Rationale: Coolant prevents overheating of both the tool and workpiece
and helps flush away chips.
4. What is the standard unit for spindle speed in CNC machines?
A. RPM
B. Revolutions per minute
C. Hz
D. M/min
Rationale: Spindle speed refers to how many revolutions per minute the
spindle makes.
5. Which G-code is used to move the tool to a specific coordinate at a
controlled feed rate?
A. G00
B. G01
, C. G02
D. G03
Rationale: G01 is a linear interpolation code for moving at a controlled
feed rate.
6. G02 is used for:
A. Linear movement
B. Clockwise circular interpolation
C. Counterclockwise circular interpolation
D. Rapid positioning
Rationale: G02 commands a clockwise arc movement in CNC machining.
7. Which part of the CNC machine holds the cutting tool?
A. Chuck
B. Spindle
C. Bed
D. Tailstock
Rationale: The spindle rotates and holds the cutting tool in place.
8. The difference between G00 and G01 is:
A. G00 is linear, G01 is circular
B. G00 is rapid movement, G01 is controlled feed
C. G00 rotates clockwise, G01 counterclockwise
D. There is no difference
, Rationale: G00 moves the tool rapidly without concern for cutting, while
G01 moves at a feed rate suitable for cutting.
9. What is the purpose of a tool offset?
A. Speed up spindle rotation
B. Adjust for tool length and diameter
C. Reduce vibration
D. Change coolant flow
Rationale: Tool offsets allow precise compensation for the tool’s actual
physical dimensions.
10. Which device measures the actual position of a CNC axis?
A. Encoder
B. Stepper
C. Servo motor
D. Linear scale
Rationale: Linear scales provide feedback on the exact position of CNC axes
for precision.
11. What does “H” represent in a tool offset?
A. Diameter
B. Height (length)
C. Helix angle
D. Hardness
Rationale: H-codes are used in tool offset tables to specify the tool length.
