Finding difficulties in memorizing things? Let's learn it in some easy ways.

Finding it difficult to remember formula of relative refractive index $$n_{21}$$? Here is an easy way to memorise it.

The path of refracted light in a denser medium can be visualised as a car moving from a smooth rode to a rough surface. This is an analogy which is stated as Fermat's principle:"light travels between two points along the path that requires the least time, as compared to other nearby paths."

This is a much easier way to remember the formula of refraction at a spherical interface:

<div>Here,</div> 
<div>R.M. is the refracting medium, which contains the refracted ray.</div> 
<div>I.M. is the incident medium, which contains the incident ray.</div>

The magnification formula can be easily memorised using I AM triangle.

We can memorise the magnifying power of a simple microscope using this mnemonic:

For compound microscope, the magnifying power can be memorised as

For telescope, the magnifying power can be memorised as

Ray Optics And Optical Instruments