The observation made by Swarali while doing the experiment are given below. Based on these write answers to the questions :
Swarali found that the light ray travelling from the denser medium to rarer medium goes away from the normal. If the angle of incidence (i) is raised by Swarali, the angle of refraction (r) went on increasing. However after certain value of the angle of incidence the light ray is seen to return back into the denser medium.
1) What is the specific value of∠i called?
2) What is the process of reflection of incident ray into denser medium called?
3)Draw the diagrams of three observations made by Swarali.
Prove the statement.
A raibow is the combined effect of the refraction, dispersion, and total internal reflection of light.
Swarali has got the following observations while doing an experiment. Answer her questions with the help of observations.
Swarali observed that the light bent away from the normal, while travelling from dense medium to rarer medium. When Swarali increased the values of angle of incidence (i), the values of angle of refraction (r) went on increasing. But at a certain angle of incidence, the light rays returned into the dense medium.
So, Swarali has some questions. Answer them –
a) Name this certain value of ‘i ’. What is the value of ‘r’ at that time ?
b) Name this process of returning of light in dense medium. Explain the process.