Question

State the approximate value of the critical angle for (a) glass-air surface, (b) water-air surface (Given ${\mu }_{glass}=1.5,{\mu }_{water}=1.33$)

• A. (a) ${49}^o$, (b)${49}^o$
• B. (a) ${42}^o$, (b)${42}^o$
• C. (a) ${42}^o$, (b)${49}^o$
• D. (a) ${49}^o$, (b)${42}^o$

Answer 1

Answer: (C)

(a) ${42}^o$, (b)${49}^o$

Critical angle is the angle of incidence from denser to rarer medium for which the angle of refraction is
These angles for glass-air interface is ${42}^o$ and water-air interface is ${49}^o$