The critical angle of light going from medium A into medium B is θ. The speed of light in medium A is v…..

Q. The critical angle of light going from medium A into medium B is θ. The speed of light in medium A is v. The speed of light in medium B is

(a) v/sinθ

(b) v sinθ

(c) v/tanθ

(d) v tanθ

Ans: (a)

Sol: μ_Asinθ = μ_Bsin90

sinθ = μ_B/μ_A    …..(i)

v_A/v_B = (c/μ_B)/(c/μ_A) = μ_B/μ_A = sinθ   from(i)

v_B = v_A/sinθ = v/sinθ