Answer:
1.208
Explanation:
L = Length of tube
c = Speed of light in air
v = Speed of light in jelly
Time taken by light in tube
[tex]\dfrac{L}{c}=8.72[/tex]
Time taken when jelly is present
[tex]\dfrac{L}{v}=8.72+1.82\\\Rightarrow \dfrac{L}{v}=10.54\ ns[/tex]
Dividing the above equations we get
[tex]\dfrac{v}{c}=\dfrac{8.72}{10.54}\\\Rightarrow \dfrac{c}{v}=\dfrac{10.54}{8.72}\\\Rightarrow n=1.208[/tex]
The refractive index of the jelly is 1.208
