# Machine Tools Questions and Answers – Classification of Drilling Machine : According to Size ( Diameter )

This set of Machine Tools and Machining online test focuses on “Classification of Drilling Machine : According to Size ( Diameter )”.

1. According to size, drill can be classified as______
a) micro drill
b) moderate drill
c) large drill
d) all of the mentioned

Explanation: Micro drill, moderate drill and large drill are the types of drill according to size. Generally, this size is expressed in micron or in mm.

2. When the size of the drill is around 25 to 500 micron,________ is used.
a) micro drill
b) moderate drill
c) large drill
d) none of the mentioned

Explanation: Micro drill has a size from 25 to 500 micron as per classification.

3. When the size of the drill is around 3 to 25 mm,________ is used.
a) micro drill
b) moderate drill
c) large drill
d) none of the mentioned

Explanation: Moderate drill has a size of 3 to 25 mm as per the classification.

4. When the size of the drill is around 25 to 40 mm,________ is used.
a) micro drill
b) moderate drill
c) large drill
d) none of the mentioned

Explanation: Generally, the large drill drill has a size from 25 to 40 mm as per classification.

5. Which of the following drill is most widely used?
a) micro drill
b) moderate drill
c) large drill
d) none of the mentioned

Explanation: Moderate type of drill is most widely used as it has medium size of drill- not too large and not too short.

6. 1 mm = ______ micron.
a) 10
b) 100
c) 1000
d) none of the mentioned

Explanation: It is the simple mathematical conversion. 1 mm = 1000 micron and 1 micron = 0.001 mm.

7. For large drills, large force should be applied.
a) true
b) false

Explanation: Large drills need large force as it has large l/d ratio.

8. In industry, which type of drill is most useful?
a) micro drill
b) moderate drill
c) large drill
d) none of the mentioned

Explanation: In industry, moderate type of drill is most widely used as it has medium size of drill and again it doesn’t need large force like large drill.

9. For large drill, how much torque is needed?
a) small
b) moderate
c) large
d) none of the mentioned

Explanation: For large drill large force is needed. As torque=force*displacement so torque is directly proportional to the force. So we need large torque for large drill.

10. For large drill, firstly hole is made by drill and then it is enlarged by boring operation.
a) true
b) false

Explanation: It is the working procedure for making large drill. Drill just make the hole. Boring is specially used for enlarging the drill that has already made by drill.

11. Large drill is a mass production machine.
a) true
b) false

Explanation: It is used only for specific purpose as it needs very large force and torque.

12. Which of the following can be used for mass production?
a) micro drill
b) moderate drill
c) large drill
d) none of the mentioned