A spring is stretched by applying a load to its free end. The strain produced in the spring is

The correct option is longitudinal and shear.

Let us analyze the behavior of a helical spring when a load is applied to stretch it:

1. Longitudinal Strain:
When a load is suspended from the free end of a spring, the spring undergoes an overall elongation along its longitudinal axis. The change in the total length of the spring relative to its initial length constitutes a macro-level longitudinal strain.

2. Shear Strain:
At the microscopic or material level, the spring is made of a wire wound into a helix. When a tensile load is applied along the axis of the helical spring, it exerts a torque (twisting moment) on the wire. This twisting of the wire induces torsional shear stress and consequently a shear strain within the material of the wire.

Therefore, the stretching of a spring involves both the macroscopic change in length along its axis and the twisting of its constituent wire, resulting in both longitudinal and shear strains.