Question

an expression of snells law from denser medium to rarer medium

Answer 1



When light travels from a denser medium to a rarer medium, it bends away fromthe normal, as illustrated to the left.  This behavior follows from Snell's Law.  As you saw before, the larger angle must be in the medium having the lower index of refraction.  On the previous pages, that was medium 1, but here it is medium 2.



Since the angle in the second medium is greater than the angle in the first medium, it can become as large as 90 degrees.  When this occurs, the first angle is called the critical angle and is represented as θc. 



If the angle θ1 in the first medium is larger than the critical angle, no light makes it into the second medium.  This condition is called total internal reflection (TIR).  Note that some reflection occurs for all angles of incidence θ1, but once θ1becomes larger than θc, all of the light is reflected from the surface.  Also be aware that total internal reflection and total reflection are not equivalent expressions.

Answer 2

to distinguish sounds having same pitch and loudness timbre or quality can be used to distinguish between the sounds . the property of sound by virtue of which we can distinguish between sounds having same loudness and pitch is called quality.