Question

give a few examples, where you use similar way to find the thickess if a single unit​

Answer 1

Explanation:

Weight difference method can be used to measure thickness. You measure mass of the film before and after deposition. The difference will give you the the mass of the film (m). You know the area of the film (A) and density (d) of the film material. By using following relation you can find out thickness (t):

t = m/Ad

The estimated thickness will be not be accurate as density of the material in bulk and thin film is different.

Answer 2

weight difference method can be used to measure thickness.you measure mass of the film before and after deposition