Question

In CBR test, the rate of penetration of plunger is _______ mm/min.

(a) 0.25

(b) 1.25

(c) 2.35

(d) 3.25

The question was posed to me at a job interview.

My question is from Flexible Pavement topic in portion Design of Flexible & Rigid Pavement of Geotechnical Engineering II

Answer 1

Correct option is (b) 1.25

Easiest explanation: The California bearing ratio test carried out in small scale in which a cylindrical plunger is of 3 in^2 or 5 cm in diameter is penetrated in to the soil mass or the sub-grade material at the rate of 1.25 mm/min or 0.05 inch per minute.