Question

A fine powder generally pass through this sieve number as per IP

• A. 44
• B. 50
• C. 85
• D. 10

Hint:

For fine powders, refer to the higher sieve numbers in pharmacopeias like IP. These sieve numbers indicate finer particle sizes.

Answer 1

The Correct Option is B

IP sieve grading runs from coarse (low sieve number) to fine (higher sieve number), so each option can be placed on that scale.

1. 44: Falls in the moderately fine range, not the fine range.
2. 50: Correct - this is the sieve number assigned to fine powder in this classification.
3. 85: Falls beyond the fine-powder cut-off in this scheme.
4. 10: Corresponds to a coarse powder, not a fine one.

So the correct answer is 50.

Answer 2

A different way to narrow this down is to first eliminate the two extreme values in the list, since a fine powder is a middle-to-upper grade, not the coarsest or the most extreme fineness grade in the same scheme.

1. 10: This is clearly the coarsest sieve number among the choices and would correspond to a coarse, not fine, powder - eliminated first.
2. 85: This is the largest sieve number among the choices, corresponding to a grade finer than what this classification labels as "fine" powder.
3. 44: Of the two remaining options, this one corresponds to the moderately fine category that sits just below the fine-powder grade being asked about.
4. 50: This is the remaining option once the coarse extreme, the overly fine extreme, and the moderately fine grade are all eliminated, placing it correctly as the fine-powder sieve number.

Eliminating both extremes and the adjacent grade isolates the same sieve number.

Hence, the correct answer is 50.