 Good morning. So today we are going to produce a concept that is a refraction of act. Basically it is a concept when unlikely moves from one medium to another medium, it bends. For example if it is moving from a railing medium say air to a water, then this incident rate will bend towards the normal. This is the normal which is the perpendicular for this interface. This is an air counter interface. It bends towards the normal. In that case angle of incident is greater than angle of refraction. But if you take a water, if a light rail is moved from water to air that is from a laser medium to a railing medium then angle of incident will be less than the angle of refraction. In that case the railing will move away from the normal. This we are going to show with the help of an activity. So I am going to put one point on it and now I am going to put a water on it. Can you see that the coin is visible? Now if we pour water on it then observe carefully the coin will be not visible to you, will become invisible to you. This is just because of refraction of light. See the coin is not visible here now. This is just because of refraction of light. Then one more activity we can show with the help of this water that if we take an arrow right now the arrow is pointing towards my right. But if you see that arrow from this water bottle then you will see the arrow towards my left hand side because of refraction of light. I hope you have enjoyed the concept. Thank you.