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### Course: AP®︎/College Physics 2>Unit 5

Lesson 3: Refraction

# Refraction through glass slab

Let's explore refraction of light through any parallel sided medium. Will also see why things appear to shift (lateral shift) when looked through such a medium.  Created by Mahesh Shenoy.

## Want to join the conversation?

• From , he asks whether the lateral shift would depend on thickness of the glass slab and the direction of the incident ray of light. I do understand how it depends on the direction of the incident ray of light but how does it depend on the thickness of the glass slab?
• If you make the medium thicker the ray will travel for longer distance at the steeper angle before returning to be parallel with the incident ray so there will be greater lateral shift. Try drawing it.
• how can you say that an incident ray is parallel to emergent ray and the angle of incidence is equal to angle of emergence. pls clarify
• You can do the activity to prove it yourself... you just need a glass slab.
• Objects seen through a glass slab appear different(distorted and closer/bigger).
But, when we see through a window made of glass, everything remains the same regardless if the window was open or closed.
Why are the two phenomena similar yet different at the same time?
(1 vote)
The shift in the image is directly proportional to thickness of glass slab. And the glass window is thin so change in image is very negligible. The bending or shift in the rays of light passing through window is not noticeable. So image doesn't appear different.
Hope it helps!
• At , I didn't understand how or why the angle formed by light bending towards the normal with respect to the incident and refracted ray = angle formed by light bending away from the normal with respect to the refracted and emergent rays
that is, how de we know that both of the angle mentioned are equal (10 degrees, here)
What if one angle was 20 and the other 10?
Please do clarify me on this.
(1 vote)
• Lets say we have a glass slab that is made up of certain materials having different density(let's say the density are arranged layer wise and the layers are having like one rarer and then one denser and bla bla). Then what will happen to the final refracted ray that comes out of the glass slab?(Taking the surrounding of glass slab to be air)
• What if we change the light degree, if i change the position of the light then the 10 degree will be different for sure. Then what will happen to the refracted light
(1 vote)
• how can we study characteristics of waves using ripple tank
• I still don't understand, I need more understanding to it.
• Why emergent ray
is parallel to refracted ray?