Question

A right angled prism is placed on a printed page as shown in figure. observer A look through the vertical face while the observer B looks through the inclined face. Identify the correct statement.

• A. IA is able to see the letters on the page then B will also see the letter
• B. If B is able to see the letters then A will also see letter.
• C. Both can see if the prism is made of glass µ = 1.5
• D. Both can see whatever the refractive index of prism is

Answer 1

Answer: (A)

IA is able to see the letters on the page then B will also see the letter

Answer 2

A can not see if ray will go for total internal reflection at vertical face.

\ (90 – g)_minmum > q_c

(90 – g)_min: 90 – g_max

90 – g_max > q_c

90 – q_c > q_c

45 > q_c

Sin 45 > Sin q_c = µ > $\sqrt { 2 }$

A can not see if µ > $\sqrt { 2 }$

For B if he can not see then 60 – g_max > q_c

60 – q_c > q_c

30 > q_c

$\frac { 1 } { 2 }$ > $\frac { 1 } { \mu }$

µ > 2

B can not see if µ > 2