Question

While tracing the path of a ray of light passing through a reactangular glass slab a student tabulated his observations. If in his experiment for two readings he takes two values of i as 40 º and 50º, what should be the correct values of e and r in each case ?

Answer 1

in case of rectangular glass slab,
refractive index of glass = sini/sinr

we know, refractive index of glass = 1.5

for , i = 40°

so, 1.5 = sin40°/sinr

or, sinr = sin40°/1.5

r = sin^-1{ sin40°/1.5 }

and we know, incident angle = emergent angle
so, e = i = 40°

similarly, for i = 50°

r = sin^-1{sin50°/1.5}

and emergent angle, e = 50°

Answer 2

the best choice would be b

the range of angle of incidence should be 30 degree to 60 degree the separation between the feet of the pins should be award 6 cm to 8 cm