after tracing the path of a ray of light passing through a rectangular glass slab for 4 different values of the angle of incidence , a student reported his observations.
S. no.      angle i     angle  r     angle e
1              30*          19*            29*
2              40*          28*            40*
3              50*          36*            50*
4              60*          40*            59*
which is the best observation?

Asked by mrinalini mrinalini | 26th Feb, 2015, 08:56: PM

Expert Answer:

For best results, the following conditions must be satisfied:
1. The angle of incidence must be nearly equal to the angle of emergence.
2. The angle of refraction must be less than the angle the incidence.
3. begin mathsize 12px style fraction numerator sin space straight i over denominator sin space straight r end fraction space equals space 1.5 space space left parenthesis since comma space the space refractive space index space of space glass space is space 1.5 right parenthesis end style
Out of the 4 observations, the first observation, that is angle i = 30° ; angle r = 19° and angle e = 29° is the correct observation.
In this case, begin mathsize 12px style fraction numerator sin space 30 degree over denominator sin space 19 degree end fraction space equals space 1.535 space end style

Answered by Yashvanti Jain | 11th Dec, 2017, 07:07: PM