Study the statements listed below 1.Area ratio should be low 2.Cutting edge should be thick 3.Outside clearance should be low The properties necessary for a good quality soil samples include
- A1 and 3Correct
- B1 and 2
- C2 and 3
- DOnly 1
Solution
Concept
Design parameters of soil samplers (Area Ratio, Inside Clearance, Outside Clearance) ensure minimum disturbance to the collected soil sample.
Formula
Area Ratio = ((D2² - D1²) / D1²) × 100
Step-by-step solution
1. Understand the criteria for undisturbed soil sampling. 2. Area ratio should be low (ideally less than 10-15%) to minimize soil displacement. 3. Cutting edge should be thin (sharp) to reduce sample disturbance, making statement 2 incorrect. 4. Outside clearance should be small (0 to 3%) to reduce friction between the soil and the sampler tube,
Why the other options are wrong
A: 1 and 3 are correct since area ratio and outside clearance should both be low.
Shortcut
Remember: Area ratio (Low), Inside clearance (1-3%), Outside clearance (0-2% or Low), Cutting edge (Thin).
Common mistake
Confusing inside and outside clearance requirements or thinking a thick cutting edge helps preserve the sample.
Correct answer: A) 1 and 3