If the plasticity index and the percentage of grain size finer than 2 microns of a clay sample are 30 and 10 respectively, then its activity ratio is
- A0.30
- B0.33
- C1.00
- D3.00Correct
Solution
Concept
Activity
Formula
A = PI / (% finer than 2 μ)
Step-by-step solution
1. A = 30/10 = 3.0.
Explanation
A = 30/10 = 3.0.
Why the other options are wrong
0.33 is the inverse.
Shortcut
A = PI/clay %.
Common mistake
Inverting the ratio.
Correct answer: D) 3.00