REFRACTION OF LIGHT

Sameer performs an experiment with the help of clear round drinking glass, pencil and tap water. He fills the drinking glass about two-thirds of the way with water. Then he place the pencil inside the glass on an angle, so it’s resting on the rim.

 

                           

He then bends down until he is looking in line with the top of the water. He observes that the pencil is broken in two.

 

Question 1- A ray of light is travelling from a rarer medium to a denser medium. What will happen?

     …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

 

 

Question 2- A light ray enters from medium A to medium B as shown in figure. The refractive index of medium B relative to A

 

(a)   greater than unity

(b)   less than unity

(c)   equal to unity
(d)   zero

Question 3- The optical phenomena, twinkling of stars, is due to

(a)   Atmospheric reflection

(b)  Total reflection

(c)   Atmospheric refraction

(d)   Total refraction

 

Question 4- Which one is optically denser in between Water and air?

 

(a)  Water

(b) Air

(c)  Both are same

(d) None of these

MARKING SCHEME:

1-    When a ray of light is travelling from a rarer medium to a denser medium, it bends towards the normal.
Correct answer - FULL CREDIT                                    (1 marks)

      Any other response- NO CREDIT

2-    (a)- FULL CREDIT, Any other response- NO CREDIT              (1 marks)

3-    (c)- FULL CREDIT, Any other response- NO CREDIT               (1 marks)

4-    (a)- FULL CREDIT, Any other response- NO CREDIT               (1 marks)