Question

In screen analysis, cumulative oversize refers to:

• A. Material retained on one screen
• B. Total material passing a screen
• C. Total material retained on a given screen and all coarser screens
• D. Difference between feed and product

Hint:

Logic Tip: "Cumulative" implies adding things up. "Oversize" means it didn't pass through. So, cumulative oversize is the sum of everything that was too big to pass through that screen and all the bigger screens above it.

Answer 1

The Correct Option is C

Concept:
Screen analysis (or sieve analysis) uses a stacked column of wire mesh screens to determine the particle size distribution of a granular material. The screens are arranged with the largest holes (coarsest) at the top and the smallest holes (finest) at the bottom.

Step 1: When a sample is poured onto a specific screen, the "oversize" fraction is the material that is too large to pass through the holes and is physically retained on top of that specific mesh.

Step 2: Because the screens are stacked sequentially, any material that reaches a specific screen has already successfully passed through all the larger screens above it.

Step 3: The term cumulative means a running total.

Step 4: Therefore, the "cumulative oversize" for a specific screen is the mass of the material retained on that specific screen plus the mass of all the material that was retained on every single larger (coarser) screen situated above it in the stack.