Ray Optics And Optical Instruments

- Finding difficulties in memorizing things? Let's learn it in some easy ways.
1
Finding it difficult to remember formula of relative refractive index ? Here is an easy way to memorise it.
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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."
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2
This is a much easier way to remember the formula of refraction at a spherical interface:
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Here,

R.M. is the refracting medium, which contains the refracted ray.

I.M. is the incident medium, which contains the incident ray.

3
The magnification formula can be easily memorised using I AM triangle.
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4
We can memorise the magnifying power of a simple microscope using this mnemonic:
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5
For compound microscope, the magnifying power can be memorised as
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6
For telescope, the magnifying power can be memorised as
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