Question

The deviation suffered by the light ray after three successive reflections in situation as shown in fig is: A) 200° clockwise B) 200° anticlockwise C) 220° anticlockwise D) 220° clockwise 200 ​

Answer 1

Answer:

220 degree   clockwise

Explanation:

Answer 2

The correct answer is option (D) 220° clockwise.

GIVEN

Angle of incidence = 50°

TO FIND

Total angle of deviation

SOLUTION

We can simply solve the above problem as follows -

It is given ,

Angle of incidence from ray 1 , i₁ = 50°

Angle of deviation, δ = 180-2i₁

= 180-100

= 80° (clockwise)

Incident ray (i₂) also goes through deviation

Therefore,

i₂ = 20°

δ₂ = 180-2(i₂)

δ₂ = 180- 40

= 140° (clockwise)

Similarly,

Angle made by incident ray 3 = i₃ = 10°

so,

δ₃ = 180-2(i₃)

= 180-2×10

= 180-20

= 160° (clockwise)

Total deviation = δ₁+δ₂+δ₃

= 80+140+160

= 220° (clockwise)

Hence, The correct answer is option (D) 220° clockwise.

#spj2