Question

a beam of light travels from air into a sheet of glass having refractive index n.

a if we increase n, the angle of incidence, decreases

b if we double the angle of incidence, the angle of reflection also doubles

c the angle of refraction will be greater than the angle of incidence \

d if the angle of incidence is large enough, the light will be totally reflected back into the air

e if we increase the angle of incidence, the angle of refraction decreases

Answer 1

(a) With increase in the value of 'n' angle on incidence also increases according to Snell's law.

(b) If we double angle on incident angle of refraction increases but not doubles.

(c) Since glass has higher refractive index than air, angle of refraction is less than angle of incident.

(d) When the angle of incedence is large enough to cross the critical angle, total internal reflection occurs and the light will be totally reflected back into air.

(e) If we increase the angle of incident, angle of refraction also increases according to Snell's law.

Hence (d) should be correct