Answer:
1.00002
Explanation:
[tex]\theta_r[/tex] = Angle of refraction = 90°
[tex]\theta_i[/tex] = Angle of incidence = (90-1.34)°
[tex]n_i[/tex] = Refractive index of incident air = 1.000293
[tex]n_r[/tex] = Index of refraction of the air immediately above the road surface
Mirages occur at the critical angle
We have the relation
[tex]n_isin\theta_i=n_rsin\theta_r\\\Rightarrow n_r=\frac{n_isin\theta_i}{sin\theta_r}\\\Rightarrow n_r=\frac{1.000293\times sin(90-1.34)}{sin90}\\\Rightarrow n_r=1.00002[/tex]
The index of refraction of the air immediately above the road surface is 1.00002