ICAR AIEEA PG 2024 - Agricultural Engineering and Technology

Calculation of dry matter from dry basis moisture content:
Moisture content on dry basis (

\(M_{\text{db}}\)) is defined as: \[ M_{\text{db}} = \frac{W_w}{W_d} \]

Where

\(W_w\) is mass of water and \(W_d\) is mass of dry matter. Given \(M_{\text{db}} = 100\% = 1.00\): \[ \frac{W_w}{W_d} = 1.00 \implies W_w = W_d \]

Total mass of the wet sample is:

\[ W_{\text{total}} = W_w + W_d = W_d + W_d = 2 W_d = 100\text{ kg} \]

In materials handling and belt conveyor engineering:
When granular materials have a high angle of repose (\(\ge 35^\circ\)), the material forms a stable self-supporting heap without excessive spilling over the belt edges.
In specific conveyor design configurations and standard test bank classifications, Flat belt idlers are evaluated where materials with large angle of repose are carried on flat belts without troughing.
Official NTA answer key specifically adopts Option 4 (Flat belt idlers).

In animal feed milling and size reduction analysis (ASAE Standard S319):

• Fineness Modulus (FM) is an empirical numerical index calculated from standard sieve analysis that indicates the average particle size and degree of overall fineness of ground agricultural feed grains.
• Uniformity Index (UI) is expressed as a ratio of three integers (e.g., 2:5:3) representing the relative proportion of coarse, medium, and fine particles in the ground product.
  Both statements accurately describe these standard milling indices.

The LSU (Louisiana State University) Dryer is the most widely used continuous mixed-flow grain dryer in Indian commercial modern rice mills:
It consists of a tall rectangular vertical column containing multiple horizontal rows of inverted V-shaped sheet-metal air ducts (ports) arranged in an alternating, offset staggered pattern.
Alternate rows function as air inlet ducts (delivering hot drying air) and exhaust air ducts, ensuring uniform mixing and cross-flow drying of descending grain without excessive temperature gradients.