Match List I with List II

Set A	Set B
[i] Robinson	[a] Pipette method
[ii] Yoder	[b] Wet sieving
[iii] Munsell	[c] Colour chart
[iv] Atterberg	[d] Consistency limits

Correct option is A

The correct answer is (A) i-a, ii-b, iii-c, iv-d

Explanation:
• Robinson (i-a): Associated with the Pipette method, which is the standard laboratory technique for mechanical analysis (determining soil texture) based on the different settling velocities of sand, silt, and clay.
• Yoder (ii-b): Developed the Wet Sieving apparatus, used to determine the water stability of soil aggregates (soil structure).
• Munsell (iii-c): Created the Munsell Colour Chart, which standardizes soil color description using three variables: Hue, Value, and Chroma.
• Atterberg (iv-d): Established the Consistency limits (Atterberg limits), which define the moisture contents at which soil changes from solid to semi-solid, plastic, and liquid states (e.g., Plastic Limit, Liquid Limit).

Information Booster:
• Munsell notation example: 10YR 4/4 (10YR is Hue, first 4 is Value, second 4 is Chroma).
• The Hydrometer method is a faster alternative to the Pipette method for texture analysis.
• Consistency limits are vital for engineering applications and determining when soil is trafficable by tractors.

Additional Knowledge:
• Stokes' Law: The physical principle underlying both the Pipette and Hydrometer methods, relating particle size to settling velocity in a liquid.