In an experiment for determination of refractive index of glass of a prism by `i-delta`, plot, it was found that a ray incident at angle `35^(@)`, suffers a deviation of `40^(@)` and that it emerges at angle `79^(@)`. In that case which of the following is closest to the maximum possible value of the refractive index ?

Options

A. `1.8`
B. `1.5`
C. `1.6`
D. `1.7`

Answer

B

Explanation

`i = 35^(@) , delta= 40^(@) , e = 79^(@)`
`delta` = i+e -A
`40^(@) = 35^(@) + 79^(@) -A`
`A = 74^(@)`
`A = 74^(@)`
and `r_(1) + r_(2) = A = 74^(@)`
solving these, we get `mu = 1.5`
Since `delta_("min") lt 40^(@)`
`mu lt (sin((74 + 40)/(2)))/("sin" 37)`
`mu_("max") = 1.44`