In a standard Califormia bearing ratio test (sample height is 125 mm ), the difference between the initial and final dial gauge readings is found to be 0. 125 mm. What is the expansion ratio of this soil?

Correct option is C

​$$\text{Expansion ratio (\%)} = \frac{\text{Change in height}}{\text{Original height}} \times 100$$
$$\text{Given:}, \text{Original height} = 125 \text{ mm}$$
$$\text{Change in height} = 0.125 \text{ mm}$$
$$\text{Expansion ratio} = \frac{0.125}{125} \times 100= 0.1$$​​​​​