A ray of light falls on the surface of water μ w a = 4 3 at angle of incidence 45 ° . What is the angle of refraction for this ray?

Refractive index of water with respect to air, μ w a = μ w μ a = 4 3 . Since refractive of air i.e μ a = 1 . . Angle of incidence, i = 45 ° . According to Snell's laws, the refractive index of a medium is given by, μ w a = s i n i s i n r . ∴ 4 3 = sin 45 ° sin r . ∴ sin r = sin 45 ° 4 3 . Thus, sin r = 1 2 4 3 ∴ sin r = 1 2 × 3 4 = 0 . 707 × 0 . 75 = 0 . 53 ≈ 1 2 . ∴ r = sin - 1 1 2 = 30 ° . Hence, the angle of refraction is approximately equal to 30 °

E M B I B E

S CHAND'S ICSE PHYSICS BOOK 2>Chapter 4 - Refraction at Plane Surfaces>QUESTIONS>Q 12

MEDIUM

10th ICSE

IMPORTANT

Earn 100

When a light falls obliquely on a glass surface it bends towards normal but when it moves out from the surface it moves away from the normal. Why? Name this phenomenon of light.

Important Questions on Refraction at Plane Surfaces

MEDIUM

10th ICSE

IMPORTANT

S CHAND'S ICSE PHYSICS BOOK 2>Chapter 4 - Refraction at Plane Surfaces>QUESTIONS>Q 13

State whether the light ray in the following diagram is moving from glass to water or vice versa. Give reason for your reason.

Question Image

HARD

10th ICSE

IMPORTANT

S CHAND'S ICSE PHYSICS BOOK 2>Chapter 4 - Refraction at Plane Surfaces>QUESTIONS>Q 14

The figure below shows refraction of a light ray from a glass slab. Write the values of angle $x$ and $y$ . What is the refractive index of the slab material?

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EASY

10th ICSE

IMPORTANT

S CHAND'S ICSE PHYSICS BOOK 2>Chapter 4 - Refraction at Plane Surfaces>QUESTIONS>Q 15

Among the following what remains constant in refraction? Amplitude, speed, wavelength and frequency of the light wave.

EASY

10th ICSE

IMPORTANT

S CHAND'S ICSE PHYSICS BOOK 2>Chapter 4 - Refraction at Plane Surfaces>QUESTIONS>Q 16

State the laws of refraction.

MEDIUM

10th ICSE

IMPORTANT

S CHAND'S ICSE PHYSICS BOOK 2>Chapter 4 - Refraction at Plane Surfaces>QUESTIONS>Q 17

A light ray is moving from air to a denser medium such that values of angle of incidence and angle of refraction are

60^{0}

and

45^{0}

respectively. What is the absolute refractive index of this medium?

HARD

10th ICSE

IMPORTANT

S CHAND'S ICSE PHYSICS BOOK 2>Chapter 4 - Refraction at Plane Surfaces>QUESTIONS>Q 18

A ray of light falls on the surface of water

({}_{a}μ_{w} = \frac{4}{3})

at angle of incidence

45^{°}

. What is the angle of refraction for this ray?

EASY

10th ICSE

IMPORTANT

S CHAND'S ICSE PHYSICS BOOK 2>Chapter 4 - Refraction at Plane Surfaces>QUESTIONS>Q 19

State the principle of reversibility.

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10th ICSE

IMPORTANT

S CHAND'S ICSE PHYSICS BOOK 2>Chapter 4 - Refraction at Plane Surfaces>QUESTIONS>Q 20

A light ray moves from water to diamond. What is refractive index of diamond with respect to water. Given refractive index of water with respect to air i.e