Question

The true density and bulk density of wheat grains are 1280 kg/m\(^3\) and 740 kg/m\(^3\), respectively. The porosity of the grains is ......... (rounded off to 2 decimal places).

Hint:

To calculate porosity, use the formula: \({Porosity} = 1 - \frac{{Bulk density}}{{True density}}\), which gives the fraction of the volume that is not occupied by the material.

Answer 1

The porosity of a material is a measure of the void spaces (or air spaces) within it, and it can be calculated using the formula:
\[ {Porosity} = \frac{1 - \frac{{Bulk density}}{{True density}}}{1} \] Where:
- Bulk density = 740 kg/m\(^3\)
- True density = 1280 kg/m\(^3\)
Substituting the given values into the formula:
\[ {Porosity} = 1 - \frac{740}{1280} = 1 - 0.5781 = 0.4219 \] Thus, the porosity of the wheat grains is approximately 0.42 (rounded to two decimal places).
Thus, the correct answer is approximately \(0.42\).