Question

draw a graph showing variations of spring force F with extension X of an ideal spring. what is SI unit of spring constant​

Answer 1

since Force = spring constant × extension in spring
F= k×X
graph for F versus X will be F/X which is K spring constant which will remain constant
and the graph will be a straight line starting from origin

SI unit for spring constant is Newton per metre
N/m

Answer 2

from Hook's law,

spring force is directly proportional to elongation or compression of spring.

if we assume F is spring force acts on it, then spring elongates or compresses x from its equilibrium position.

from Hook's law, $F\propto x$

$\implies F=kx$

here, k is spring constant.

hence, graph between force and extension of spring is a straight line as shown in figure.

from graph, it is clear that force will be negative when spring is compressed and force will be positive when spring is elongated.

si unit of spring constant, k = si unit of force/si unit of extension (length)

= N/m