Answer:
C. 1.15
Explanation:
The formula for the critical angle is:
[tex]{sin\theta_{critical}}=\frac {n_r}{n_i}[/tex]
Where,
[tex]{\theta_{critical}}[/tex] is the critical angle
[tex]n_r[/tex] is the refractive index of the refractive medium. ( Alcohol , ? )
[tex]n_i[/tex] is the refractive index of the incident medium. ( Glass, 1.66 )
Critical angle = 44º
Applying in the formula as:
[tex]{sin\theta_{critical}}=\frac {1}{1.523}[/tex]
[tex]{sin\ 44^0}=\frac {n_r}{1.66}[/tex]
[tex]{n_r}=1.15[/tex]