Soil Physics & Water Relations

Percent porespace is calculated as [1 - (Bulk Density / Particle Density)] x 100 = [1 - (1.55 / 2.60)] x 100 = 40.4%.

• 40.4: Pore space (%) = [1 - (1.55 / 2.60)] x 100 = [1 - 0.59615] x 100 = 40.385% ~ 40.4%.
• 55.8: Calculation error.
• 44.2: Calculation error.
• 59.6: Represents the percentage of solid space (1.55 / 2.60 x 100 = 59.6%), not pore space.

• Sandy loam contains 50 to 70 percent sand.
• Loamy sand contains 70 to 85 percent sand.
• Silt clay loam contains the lowest proportion of sand (typically less than 20% sand, consisting of 27-40% clay and 40-73% silt) among the listed textural classes. Note: This question was dropped by RPSC due to a discrepancy between the English version ('minimum sand content') and the Hindi version (' ').
• Silt loam contains up to 50 percent sand.

• In the Munsell Soil Color notation (Hue Value/Chroma), Chroma represents the relative purity or saturation of the spectral color. In standard soil charts, Chroma is numbered on a scale from /0 (neutral achromatic gray) up to /8 (pure spectral hue).
• Chroma begins at 0 for neutral colors, not 1.
• Value (lightness from pure black 0/ to pure white 10/) ranges from 0 to 10.
• 10 is an incorrect scale for chroma.

• Pumice is an extrusive, highly vesicular volcanic igneous rock formed when gas-rich silicic lava is explosively ejected and solidifies rapidly, trapping countless gas microvesicles that yield a bulk density < 1.0 g/cm3, allowing it to float on water.
• Sedimentary rocks form from deposition and cementation of mineral particles.
• Metamorphic rocks form under high temperature and pressure without melting.
• Pumice is exclusively igneous.