What is defined as the amount of tightening force applied between the bearing plate and the anchor of a roof bolt?

The correct answer is defined as the amount of tightening force applied between the bearing plate and the anchor of a roof bolt, which is commonly referred to as tension. In the context of mining and roof bolting, tension is the force exerted along the length of a bolt, caused by the tightening of the nut against the bearing plate. This tension is critical for ensuring the stability of the roof support system because it helps resist both shear forces and potential roof failures.

When a roof bolt is installed, the application of tension ensures that the bolt is secure, contributing to the overall integrity of the mine's roof. Proper tension allows the bearing plate to effectively distribute loads and support the rock strata above it.

In contrast, other options like torque refers to the rotational force applied to achieve the tension but does not directly describe the tightening force between the bearing plate and the anchor itself. Maximum load relates to the ultimate capacity of the bolt and may refer to failure points, while pressure typically refers to force applied per unit area, which is not the same as the tensile force exerted in this context.