For the same angle of incidence the angles fo refreaction in media P,Q ,R and S are `50^(@) ,40^(@),30^(@),20^(@)` respectively the speed of lights is minimum in medium

Options

A. P
B. Q
C. R
D. S

Answer

D

Explanation

`n=(v_a)/(v_m) and n=(sin i)/(sin r)`
`:. v_("medium")=(v_a)/(n)=(v_a)/(sin i) xx sin r`
But `v_a and sin i` are constant . `:. v_(m) prop sin r `
`:. 50^(@) gt 40^@ gt 30^(@) gt 20^(@)`
`:. v_p gt v_Q gt v_R gt v_S `
`:. `THe speed of light is minimum in the medium 'S'.