What is the refractive index of glass to water, given that the refractive index of water is and the refractive index of glass is ?3 2
4 3
SAMPLE ANSWER 13B , where and are the refractive indices of glass and water respectively.
ang 3 2 and anw 4
3
gnw gna anw 1 ang
ang
anw 2 3
anw Using the formula gnw gna anw we get:
4 3 8
9
The refractive index from glass to water is .8 9
Real and apparent depth
An object will appear less deep when viewed through glass or water because at the surface of the transparent medium the rays of light coming from the object are refracted.
Air S
Q P Object
Air Q Water Q P Q P Object P Fig 13.4: Viewing an object submersed in water
If an object is viewed from the air through a medium (water, for example) and the line of view is perpendicular to the surface of the medium, then:
REFRACTIVE INDEX
refractive index real depth apparent depth
SCIENCE,TECHNOLOGY & SOCIETY
Examples of refraction of light If you have ever looked into a lake at fish swimming around, they appear closer to the surface of the water than they really are. As a result they appear slightly magnified.The same phenomenon can be observed if you place a glass prism on this textbook.The words appear closer to you and the letters are slightly bigger.
