How to draw a ray diagram

 

Asked by Divya | 12th Jan, 2018, 11:36: AM

Expert Answer:

Ray diagrams are drawn to illustrate the path of light due to reflection of mirror and refraction of transperent medium like glass and water.
 
To draw the ray diagram, we should know the proporties of reflecting and refracting medium, properties like focal length, refractive index etc.
 
example of refraction in prism of glass 
 
 we know light ray incident on one side and we should consider the following proporties.
 
(1) refraction taking place inside prism at point of incidence and point of emergence. 
(2) light ray entering from lighter medium to denser medium, hence light ray deviates towards the normal drawn at the point of incidence.
(3) angle of refraction can be calculated from snells formula for the given angle of incidence.
(4) angle of incidence inside prisism at exit point is same as angle of refraction at incident point.
(5) if angle of incidence at exit point of prism is greater than critical angle total internal reflection takes place, else refraction takes place.
(6) if refraction takes place at exit point, since the ray is travelling from denser medium to rare medium, light ray deviates away from normal drawn at the point of exit.
 
The above mentioned properties are to be considered as rules for making ray diagram.
 
Refer your text book for the given properties to be followed to make ray diagram for glass slab, spherical mirrors and spherical lenses.
 
 

Answered by Thiyagarajan K | 12th Jan, 2018, 12:23: PM

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