Question

question 90 of 100 · multiple choice

the speed of a drill press is adjusted based on?

a type of material and size of drill bit

b thickness of material and size of drill bit

c thickness of material and length of drill bit

d type of material and length of drill bit

Explanation:

Identify the factors determining drill press speed

The cutting speed (RPM) of a drill press is calculated using the formula:

$$ \text{RPM} = \frac{4 \times \text{Cutting Speed (CS)}}{\text{Diameter of Drill Bit (D)}} $$

where Cutting Speed (CS) depends entirely on the type of material being drilled (e.g., steel, aluminum, wood), and \(D\) is the size (diameter) of the drill bit.

Evaluate the given options

• Option A: Correctly identifies both the type of material (which determines cutting speed) and the size of the drill bit (diameter).
• Option B: Incorrectly substitutes thickness of material for type of material.
• Option C: Incorrectly uses thickness and length of the drill bit.
• Option D: Incorrectly uses length of the drill bit instead of size (diameter).

Answer:

• (A) type of material and size of drill bit (Correct answer)
• (B) thickness of material and size of drill bit
• (C) thickness of material and length of drill bit
• (D) type of material and length of drill bit