Question

explanation needed...... ​

Answer 1

$\underline{\pink{Given:-}}$

Ratio of refractive indices of two media = 2:1

Angle of incidence = 30°

$\underline{\blue{To \: Find:-}}$

The angle of refraction.

$\underline{\red{Knowledge\: required:-}}$

↗ sin i/sin r = constant for any pair of media and for light of a given wave length.

(snell's law)

✧$\underline{\pink{n₁ \:sin \: i = n₂sin \:r}}$

Where,

↝ i is angle of incidence

↝ r is angle of refraction

Now,

➝n₁sin i = n₂sin r

➝ n₁/n₂ × sin i = sin r

➝sin r = 2/1 × sin30°

➝sin r = 2 × 1/2

➝sin r = 1

☞ $\underline{\pink{\boxed {r = 90°}}}$

___________________________

Note:-

• Diagram is in attachment.kindly go throw the diagram to understand more clear.

Answer 2

Answer :

Ratio of refractive indices of two media = 2:1

Angle of incidence = 30°

We have to find angle of refraction

★ sin i/sin r = constant for any pair of media and for light of a given wave length. This is known as snell's law.

• n₁sin i = n₂sin r

i denotes angle of incidence

r denotes angle of refraction

⭆ n₁sin i = n₂sin r

⭆ n₁/n₂ × sin i = sin r

⭆ sin r = 2/1 × sin30°

⭆ sin r = 2 × 1/2

⭆ sin r = 1

⭆ r = 90°

Hence, option D is correct.