CNC/DNC Technology - Mechanical Engineering (MCQ) questions and answers

1)   In NC (Numerical Control) machine tool, the position feedback package is connected between

a. control unit and programmer
b. programmer and machine tool
c. control unit and machine tool
d. programmer and process planning
Answer  Explanation 

ANSWER: control unit and machine tool

Explanation:
No explanation is available for this question!


2)   Several machine tools can be controlled by a central computer in

a. NC (Numerical Control) machine tool
b. CNC (Computer Numerical Control) machine tool
c. DNC (Direct Numerical Control) machine tool
d. CCNC (Central-Computer Numerical Control) machine tool
Answer  Explanation 

ANSWER: DNC (Direct Numerical Control) machine tool

Explanation:
No explanation is available for this question!


3)   Arrange the below operations in operator controlled machine tool in correct order.

(A) Operator
(B) Process planing
(C) Machine tool
(D) Component drawing
(E) Completed component


a. (A) – (D) – (B) – (C) – (E)
b. (D) – (B) – (C) – (A) – (E)
c. (B) – (D) – (C) – (A) – (E)
d. (D) – (B) – (A) – (C) – (E)
Answer  Explanation 

ANSWER: (D) – (B) – (A) – (C) – (E)

Explanation:
No explanation is available for this question!


4)   The device, fed to the control unit of NC machine tool which sends the position command signals to sideway transmission elements of the machine, is called as

a. controller
b. tape
c. feedback unit
d. none of the above
Answer  Explanation 

ANSWER: tape

Explanation:
No explanation is available for this question!


5)   Which of the following options is correct for the control unit and panel of NC (Numerical Control) and CNC (Computer Numerical Control) machine tools?

a. The control unit of NC machine tool works in ON-line mode and the control unit of CNC machine tool works in batch processing mode
b. The control unit of NC machine tool works in batch processing mode and the control unit of CNC machine tool works in ON-line mode
c. The control units of both NC and CNC machines work in ON-line mode
d. The control units of both NC and CNC machines work in batch processing mode
Answer  Explanation 

ANSWER: The control unit of NC machine tool works in batch processing mode and the control unit of CNC machine tool works in ON-line mode

Explanation:
No explanation is available for this question!


6)   In CNC machine tool, the part program entered into the computer memory

a. can be used only once
b. can be used again and again
c. can be used again but it has to be modified every time
d. cannot say
Answer  Explanation 

ANSWER: can be used again and again

Explanation:
No explanation is available for this question!


7)   Which of the following statements are correct for CNC machine tool?

1. CNC control unit does not allow compensation for any changes in the dimensions of cutting tool
2. CNC machine tool are suitable for long run applications
3. It is possible to obtain information on machine utilization which is useful to management in CNC machine tool
4. CNC machine tool has greater flexibility
5. CNC machine can diagnose program and can detect the machine defects even before the part is produced


a. (1), (2) and (3)
b. (2), (4) and (5)
c. (3), (4) and (5)
d. (2), (3), (4) and (5)
Answer  Explanation 

ANSWER: (3), (4) and (5)

Explanation:
No explanation is available for this question!


8)   Part-programming mistakes can be avoided in

a. NC (Numerical Control) machine tool
b. CNC (Computer Numerical Control) machine tool
c. Both a. and b.
d. None of the above
Answer  Explanation 

ANSWER: CNC (Computer Numerical Control) machine tool

Explanation:
No explanation is available for this question!


9)   The machine tool, in which calculation and setting of the operating conditions like depth of cut, feed, speed are done during the machining by the control system itself, is called

a. Computer Numerical Control System
b. Direct Numerical Control System
c. Machining Centre System
d. Adaptive Control System
Answer  Explanation 

ANSWER: Adaptive Control System

Explanation:
No explanation is available for this question!


10)   Which machine tool reduces the number of set-ups in machining operation, time spent in setting machine tools and transportation between sections of machines?

a. Computer Numerical Control machine tool
b. Direct Numerical Control machine tool
c. Adaptive Control Systems
d. Machining centre
Answer  Explanation 

ANSWER: Machining centre

Explanation:
No explanation is available for this question!