Question

Noor, a young student, was trying to demonstrate some properties of light in her Science project work. She kept ‘X’ inside the box (as shown in the figure) and with the help of a laser pointer made light rays pass through the holes on one side of the box. She had a small butter-paper screen to see the spots of light being cast as they emerged.

She measured the angles of incidence for both the rays on the left side of the box to be 48.60. She knew the refractive index of the material ‘X’ inside the box was 1.5. What will be the approximate value of angle of refraction?

(use the value: sin 48.6° ≈ 0.75)

पर्याय

• 45°

• 40°

• 30°

• 60°

Answer 1

30°

Explanation:-

Refractive index of medium `=sini/sinr`

`1.5=sin48.6^circ/sinr`

`1.5=0.75/sinr`

`sinr=0.75/0.5`

sin r = 0.5

r = sin^-1(0.5)

r = 30°