Question #354d2

2 Answers
Jan 14, 2018

41.81 degrees

Explanation:

enter image source here Critical angle of light is that one,if at that angle light falls at an interface,while going from a solid to lighter media,it will not enter the media next to the interface,rather go along the interface,

So,using Snell's law we can say,
u1 sin theta = u2 sin alpha
Given, u2 = (3/2)
And sin theta = 1
So, sin alpha = 2/3 or alpha = 41.81 degrees

Jan 14, 2018

the critical angle is i_c=42.067

Explanation:

critical angle i_c is given as
sin(i_c)=1/n_21 where n_21=n_2/n_1
n is the refractive index of that particular media
here n_2=3/2 and n_1=1 substituting in the formula we get
sin(i_c)=(1/(3/2))=(2/3)rArri_c=sin^-1(2/3)=sin^-1(0.67)
rArri_c=42.067