Machine Dynamics Multiple Choice Questions on “Programme using Least Square Technique”.
1. The sum of the shape functions over the element is always equal to:
a) Zero
b) Infinity
c) Unity
d) None of the mentioned
Answer: c
Clarification: A shape function is always equal to one at its designated node and zero at the other nodes of the element.
2. Stiffness is ______________ to the length of the element.
a) Inversely proportional
b) Directly proportional
c) Exponential
d) Independent
Answer: d
Clarification: None.
3. Computer will perform the data processing functions in
a) NC
b) CNC
c) DNC
d) ACS
Answer: c
Clarification: In NC it performs numerical problems.
In DNC it will perform data processing functions.
4. The first commercial CNC machine was developed in the year:
a) 1970
b) 1972
c) 1976
d) 1980
Answer: a
Clarification: The first NC machines were built in the 1940s and 1950s.
CNC was developed in 1970.
5. CNC drilling machine is considered to be a:
a) Point-to-point controlled machine
b) Straight line controlled machine
c) Continuous path controlled machine
d) Servo-controlled machine
Answer: a
Clarification: None.
6. The lost motion in CNC machine tool is on account of:
a) Backlash in gearing
b) Wind-up of drive shafts
c) Deflection of machine tool members
d) All of the mentioned
Answer: a
Clarification: The system must provide sufficient feedback and programming capacity to allow for backlash and lost motion between motor and load. Computer numerical control (CNC) of machine tools has embodied position control for a number of years.
7. The axes of turning machine arc:
a) Z and X-axes
b) X and Y-axes
c) Z and Y-axes
d) X, Y and Z-axes
Answer: a
Clarification: None.
8. On turning lathes the machine zero point is generally at the:
a) Head stock of lathe spindle nose face
b) Dead center of tail stock
c) Tool point mounted on tool post
d) none of the mentioned
Answer: b
Clarification: On turning lathes, the machine zero point is generally at the centre of the spindle nose face.
9. Dwell is defined by:
a) G04
b) G03
c) G02
d) G01
Answer: a
Clarification: G02 – Circular interpolation in clockwise direction
G91 – incremental dimension.
10. M30 stands for:
a) End of program
b) End of block
c) End of tape and tape rewind
d) Coolant on/ off
Answer: a
Clarification: M30 – Program Stopping and Ending.