Question

The angle of slope up to which the materials are stable in a slope is called __________

(a) Shear angle

(b) Angle of failure

(c) Critical angle

(d) Sub-angle

This question was posed to me during an internship interview.

The above asked question is from Causes of Mass Movements in section Mass Movements of Engineering Geology

Answer 1

The correct option is (c) Critical angle

To explain I would say: It has been observed that most materials are stable up to a certain angle of slope. This is called the critical angle of slope or also called as angle of repose and varies from 35° for unconsolidated sediments to 90° for perfectly crystalline unjointed rocks.