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WorksheetsFundamentals of CNC Machines-Sessional-1
Total questions: 30
Worksheet time: 19mins
The CNC stands for
Computerized Numerical Control
Computerized Note Control
Controlled Numerical Computer
Computerized Number Count
What are the advantages of a CNC machine?
Reduced scrap rate
Higher flexibility
Improved quality
All of these
Which machine tools/ operations are basically handled and controlled by CNC
Lathe
Milling
Grinding
All of the above
In CNC machine tool, the part program entered into the computer memory
can be used again but it has to be modified every time
can be used again and again
cannot say
can be used only once
Why is CNC Machining necessary?
To manufacture complex shapes
High precision is required
To increase productivity
All of these
What is true about a CNC machine?
The slideways operate under high friction
Backlash is very high
CNC machines are more rigid than conventional machine
None of these
What is the advantage of a ball screw?
The power transmission efficiency is less
It is not self-locking screws
High levels of lubrication is required
The friction is very less
Preloading of ball screw is done to
reduce the friction
increase the friction
reduce the backlash
increase the backlash
A series of coded instructions required to produce a part in a CNC machine is known as
C program
part program
part line
end of block
MCU in CNC stands for
Manual Control Unit
Mobile Control Unit
Machine Control Unit
None of these
The function of MCU is
to write the part program
to read and decode the coded instructions
to edit the part program
to start the machine
In the CNC machine tool
the spindle rotates about Z-axis
the spindle rotates about Y-axis
the table moves along the Z-axis
the spindle rotates about X-axis
The position and speed transducers to continuously monitor the position at which the cutting tool is located at any particular instant are the part of
Part program
Machine Control Unit
Feed Back System
None of these
A drive system consists of
amplifier circuits
drive motors
ball lead-screws
all of these
The essential requirement of a stepper motor is
the angular position of the rotor changes in steps
the rotation of the rotor is continuous
the friction is very less
none of these
What is the use of POS key?
To check the X-coordinate and Y-coordinate
To stop the spindle
To change the tool
To end the program
The INPUT key is used to
change any value in the part program
change the tool
enter the codes from USB to machine
start the spindle
The SYSTEM key is used
to load the part program
to edit the part program
to switch off the machine
by PLC programmer for setting in the machine
PLC stands for
Programmable Logic Computer
Programmable Logic Controller
Primary Logic Controller
Programmable Language Controller
The code used in a part program to define incremental mode is
G89
G90
G91
G92
The code used to define the absolute mode of a part program is
G89
G90
G91
G92
In which of the following operation, a point-to-point positioning system is used?
Milling
Drilling
Turning
None of these
The continuous positioning system is used in
Drilling
Punching
Milling
None of these
The method by which a machine tools move from one programmed point to the next is called
Translation
Interpolation
Transformation
Rotation
Each line describing a particular set of machining operations in a part program is called
Code
Address
Block
Word
G- codes are also known as
German function
Preparatory function
Miscellaneous function
None of these
The code used for linear interpolation is
G00
G01
G02
G03
The code used for circular interpolation in a clockwise direction is
G00
G01
G02
G03
The code used for tool change is
M00
M04
M05
M06
The spindle can be stopped using the code
M05
M06
M07
M08
