It is a wire wound in spiral form which can undergo considerable deflection without getting permanently distorted.

It is the load per unit deflection which is also known as the stiffness of the spring.

Helical springs are classified into two groups. Select all that applies.

For two or more springs in PARALLEL, the resulting spring constant is given as:

For two or more springs with spring laid in SERIES, the resulting spring constant k is given as:

It is the type of helical spring in which the helix angle is less than about 10° and it experiences too little bending or direct shear stress.

It is the type of helical spring in which the helix angle is significant and it experiences both torsional and bending stresses.

A close coiled helical spring is made of 5mm diameter wire. It is made up of 32 coils, each having a mean diameter of 60mm. Determine the proof load of the spring if the maximum stress in the spring is not to exceed 200MPa. Use G= 80 GPa.

An open-coiled helical spring consists of 10 turns with a radius of 80mm and diameter of the wire is 10mm, while the angle of helix is 18 Degrees and is subjected to an axial load of 250 N. Determine the deflection under the load if E=210 GPa and G=84 GPa.