The value of force constant between the applied elastic force F and displacement will be

According to Hooke's law of elasticity, the applied elastic force $F$ is directly proportional to the displacement $x$ within the elastic limit.

This relationship is mathematically expressed as:

$F=kx$

where $k$ is the force constant.

Solving for the force constant $k$, we get:

$k=\frac{F}{x}$

In a graph plotting the force $F$ along the vertical axis and the displacement $x$ along the horizontal axis, the force constant $k$ represents the slope of the straight line. If the line makes an angle of 30° with the displacement axis (x-axis), the slope is given by the tangent of that angle:

$k=\tan (30°)$

Evaluating the trigonometric function gives:

$k=\frac{1}{\sqrt{3}}$

Thus, the value of the force constant is 1/√3.