Question

Kelper used total internal reflection in a glass block to deflect a beam of light as shown in the figure. For an angle of the incidence $i$ at the top surface, the minimum refractive index $\left(n\right)$ needed for total internal reflection at the vertical surface is (the surrounding medium is air for which $n=1$)

• A. $n=1+si{n}^{2}i$
• B. $n=\sqrt{1+si{n}^{2}i}$
• C. $n=\sqrt{1+co{s}^{2}i}$
• D. $n=1+co{s}^{2}i$

Answer 1

The correct option is B $n=\sqrt{1+si{n}^{2}i}$

Option B is correct