Answer:
1.27
Explanation:
[tex]n_{g}[/tex] = Index of refraction of glass = 1.4
[tex]n_{e}[/tex] = Index of refraction of ethanol = ?
i = Angle of incidence = critical angle = 65° deg
r = Angle of refraction = 90° deg
Using Snell's law
[tex]n_{g}[/tex] Sini = [tex]n_{e}[/tex] Sinr
(1.4) Sin65 = [tex]n_{e}[/tex] Sin90
[tex]n_{e}[/tex] = 1.27
