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Refraction of Light

Refraction through two layers

First Scene – Kill enemies by changing the refractive index of Material B. Angle of incidence is fixed at 45 degree. Increase refractive index to bend it towards the normal or decrease the refractive index to bend it away from the normal. Do not decrease refractive index below 1.41 as for a light ray travelling from Material A (R.I. = 2) to Material B (R.I. = 1.40) critical angle is 44.4 degree and since angle of incidence is 45 degree total internal refraction will occur.

Second Scene – Kill enemies by increasing refractive index to bend it towards the normal or by decreasing the refractive index to bend it away from the normal. BUT as angle of incidence is changing take care not the decrease the refractive index such that the critical angle is exceeded by the angle of incidence.

Refraction through a glass slab

Kill enemies by changing the height and refractive index of the slab.

Refraction through multiple layers, kill all enemies by arranging layers in the order from top –

First scene – Germanium, zirconium, ice, flint glass
Second scene – Zirconium, ice, germanium, flint glass
Third scene – Flint glass, ice, germanium, zirconium
Fourth scene – Ice, zirconium, germanium, flint glass

Multiple choice questions

  • The velocity of light is fastest in which medium?
    Answer: Air
  • When light is passing from a rarer medium to a denser medium,  the velocity of light:

Answer: Decreases

  • When light is passing from a denser medium to a rarer medium, the velocity of light:

Answer: Increases

  • The velocity of light in air is ___________

Answer: 3 X 10 to the power 10 cm/s

  • The intensity of the refracted light is always ______ than, the intensity of the incident light.

Answer: Lesser

  • In which medium does light travel fastest out of the following: kerosene n = 1.44, turpentine n = 1.47 and water n = 1.33

Answer: water

  • If the refractive index of two media are equal then:

Answer: no refraction will occur

  • Light is refracted when it travels from water to air at an angle because:

Answer: its speed increases

  • According to Snell’s law the relation between angle of incidence and angle of refraction is:

Answer: sine of angle of incidence / sine of angle of refraction = refractive index

  • The correct relationship between refractive index and speed of light is:

Answer: n = c/v

  • When light is traveling through a glass slab as the angle of incidence increases:

Answer: lateral displacement increases

  • When light is passing through a glass slab, as the thickness of slab increases the lateral displacement will:

Answer: increase

  • Which is optically denser between water and air?

Answer: Water

  • The change of direction of light when travelling from one transparent medium to another transparent medium is called:

Answer: Refraction

  • A coin dipped in water appears raised because of:

Answer: refraction of light

  • A naturally occurring optical phenomenon in which light rays are bent to produce a displaced image of distant objects is called:

Answer: mirage

  • When angle of incidence is equal to the critical angle then angle of refraction becomes:

Answer: 90 deg.

  • Diamond has a high refractive index hence its critical angle will be:

Answer: low

  • When total internal reflection occurs, the angle of incidence is:

Answer: more than the critical angle

  • The refractive index of glass with respect to air is 3/2. The refractive index of air with respect to glass will be:

Answer: 2/3

  • The quantity that does not change during refraction is:

Answer: frequency

  • A ray of light traveling perpendicular to the boundary of a parallel glass slab will:

Answer: not get refracted

  • A ray of light bends away from normal when it goes from medium A to medium B. Which is correct statement?

Answer: A is glass B is air

  • If the angle of incidence of a ray of light falling on a glass surface is 30 deg. and angle of refraction in 19 deg. What is the refractive index of glass?

Answer: 1.53

  • If the angle of incidence of a ray of light falling on a glass surface is 45 deg. and angle of refraction in 30 deg. What is the refractive index of glass?

Answer: 1.41

  • If the angle of incidence of a ray of light falling on a glass surface is 45 deg. and angle of refraction in 60 deg. What is the refractive index of glass?

Answer: 1.22

  • The angle of incidence of a ray of light falling on a plastic slab is 40 deg. and angle of refraction of refracted ray is 26 deg. What is the ref index of the plastic?

Answer: 1.46

  • If a ray of light falls on a transparent glass slab at an angle of 60 deg. with the normal, find angle of refraction if, given, refractive index of glass is 1.5.

Answer: 35.2 degrees

  • The refractive index for a plastic slab is 1.6. If angle of incidence is 54 deg. the angle of refraction will be?

Answer: 30.3 degrees

  • If a ray of light falls on a transparent glass slab at an angle of 45 deg. with the normal, find angle of refraction if, given, refractive index of glass is 1.6.

Answer: 26.2 degree

  • If a ray of light falls on a transparent glass slab at an angle of 30 deg. with the normal, find angle of refraction if, given, refractive index of glass is 1.5.

Answer: 19.4 degree

  • Refractive index of water is 1.33 and that of air is 1. What is the critical angle for water air boundary?

Answer: 48.7 degree

  • Refractive index of diamond is 2.4 and that of air is 1. What is the critical angle for diamond air boundary?

Answer: 24.6 degree

  • The critical angle of sapphire is 34.4 deg. What is its refractive index?

Answer: 1.77

  • The ref index of glass is 1.5 its critical angle is?

Answer: 41.8

  • What is the speed of light traveling in a glass of refractive index = 1.5?

Answer: 2 X 10 to the power 8 m/s

  • Calculate the speed of light in water if it’s refractive index is 1.33.

Answer: 2.25 X 10 to the power 8 m/s

  • The speed of light in air is 3 × 10 to the power 8 m/s. What will be the speed of light in glycerine, whose refractive index is 1.47?

Answer: 2.04 x 10 to the power 8 m/s

  • The speed of light in air is 3 × 10 to the power 8 m/s. What will be the speed of light in ethyl alcohol, whose refractive index is 1.36?

Answer: 2.20 x 10 to the power 8 m/s

  • Light travels through water with a speed of 2.25 X 10 to power 8 m/s. What is the refractive index of water?

Answer: 1.33