EX12B Refraction of Light

Refraction is the ​ (a)   in the ​ (b)   of light when it passes from one medium to another, due to ​ (c)   in light speed.

• change
• direction
• increase
• reduction
• intensity
• colour

The laws of refraction states that:

1. The incident ray, the refracted ray and the normal at the point of incidence all lie in the ​ (a)   .

2. For two given media, the ratio ​ (b)   is​ (c)   , where i is angle of incidence and r is angle of refraction.

• same plane
• 𝒔𝒊𝒏⁡ⅈ/𝒔𝒊𝒏⁡𝒓
• constant
• different plane
• same angle
• different angle
• not constant
• 𝒔𝒊𝒏⁡𝒓/𝒔𝒊𝒏⁡ⅈ

Which diagram correctly shows how light is refracted when it passes from one medium to another?

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Which diagram correctly shows how light is refracted when it passes from one medium to another?

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Which diagram correctly shows how light is refracted when it passes from one medium to another?

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The diagrams show an incident ray striking the surfaces of water.

Angle of incidence, i = ​ (a)  

Angle of refraction, r = ​ (b)  

refractive index of water = (​ (c)   /​ (d)   ) = 1.32

• 60°
• 41°
• sin 60°
• sin 41°
• 30°
• 49°
• sin 49°
• sin 30°

The diagrams show an incident ray striking the surfaces of glass.

Angle of incidence, i = ​ (a)  

Angle of refraction, r = ​ (b)  

refractive index of water = (​ (c)   /​ (d)   ) = 1.32

• 60°
• 35°
• sin 60°
• sin 35°
• 30°
• 55°
• sin 55°
• sin 30°

A ray of light passes through a rectangular glass block as shown.

Angle of incidence = ​ (a)  

Angle of refraction = ​ (b)  

Refractive index of glass = (​ (c)   ) / (​ (d)   )

• 60°
• 35°
• sin 60°
• sin 35°
• 30°
• 55°
• 150°
• 125°
• sin 30°
• sin 55°

The figure below shows a ray of light, in air, incident on a glass block with an angle of incidence of 50°.

Given that the refractive index of the glass block is 1.52, the angle of refraction r can be found by the following:

1.52 = (​ (a)   ) ​ (b)   (​ (c)   )

• sin 50°
• /
• sin r
• ×
• +
• -
• 50°
• r