8C: Light & Optical Systems Flashcards

1
Q

What are the properties of light?

A
  1. Light is a form of energy.
  2. Light exists as tiny particles called photons.
  3. Light travels in straight lines called rays.
  4. Shadows form when light rays are blocked.
  5. Light travels faster than sound
  6. Luminous objects give off their own light. Non-luminous objects only reflect light.
  7. When light strikes an object, it can be reflected, transmitted or absorbed.
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2
Q

What the difference between a non-luminous and luminous object?

Can you provide an example of each?

A

A luminous object emits or produces its own light rays.

ex) sun, lightbulb, flashlight, tv, etc.

A non-luminous object relies on a luminous object because they must reflect the incoming light rays.

ex) moon, desk, Mr. Foisy, etc

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3
Q

When light travels towards an object, three specific things can happen. What are they?

A

Light can either be:

  • Reflected
  • Absorbed
  • Transmitted (passes through)
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4
Q

What is a diffuse reflection?.

A

Diffuse reflection is the reflection of light from an irregular surface so that an incident ray is reflected at many different angles.

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5
Q

What are the colors in the visible color spectrum?

A

ROYGBIV

-Red, Orange, Yellow, Green, Blue, Indigo, Violet

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6
Q

What is the difference between transparent, translucent, and opaque materials?

A
  • Transparent: transmit nearly all of the light.
  • Transluscent: transmits some of the light, but scatters it.
  • Opaque: do not transmit any light – they block it.
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7
Q

What types of surfaces follow the law of reflection and demonsrate regular reflection?

A

Smooth and shiny surfaces reflect light rays at the same angle.

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8
Q

What does this image represent?

A

The Law of Reflection

(Angle of Incedence=Angle of Reflection)

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9
Q

When light is transmitted through a transluscent object it is often refracted. True or False?

A

True.

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10
Q

Absorption means to block light rays. True or False?

A

True.

(Colored objects appear that way because they absorb some colors but reflect others).

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11
Q

White light is made up of 7 different colors. True or False?

A

True.

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12
Q

Explain what happens when white light passes through a triangular prism.

A

The prism splits the white light into its colors because the white light gets refracted into its primary components. You will be able to witness the visible light spectrum.

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13
Q

What are the primary colours of light?

A
  • Red
  • Blue
  • Green
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14
Q

Explain what an incident ray is.

A

The ray of incidence is described as the incoming light ray in a ray diagram or optical device.

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15
Q

The primary colors of light are cyan, yellow, and magenta. True or False?

A

False.

These colours are created by mixing the 3 primary colours of light (R,B,G).

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16
Q

Why can images become visible when light is projected through a gas that contains dust/other particles?

A

The light becomes blocked by the solid particles and is either absorbed or reflected. In addition, some gases have a different refractive index.

17
Q

What is refraction?

A

When light rays pass through one object to another the light bends because it changes speed in the different materials (mediums).

18
Q

Lenses are useful because they can refract light rays in a predictable way.

True or False?

A

True.

19
Q

A concave lens is ________ in the middle.

A convex lens is _________ in the middle.

A

thinner

thicker

20
Q

Where does “bad” light go???

A

To Prism….

21
Q

Who was Archimedes and what did he try to accomplish using mirrors and lenses?

A

He was an ancient Greek philosopher who attempted to focus light with mirrors and lenses in order to burn down enemy Chinese ships.

22
Q

Mathmatician Pythagoras believed that humans were able to see objects because …?

A

Light beams came from our eyes. (This did not explain why humans were not able to see well in the dark).

23
Q

Ptolemy discovered how light beams ____________ when they travel from air to glass.

A

Bend/Refract

24
Q

al-Haytham was an Arab scientist who was one of the first to accurately do what?

A

Describe how vision worked.

25
Q

Who discovered that white light is actually made up of colours by shining it through a triangular prism?

A

Sir Isaac Newton

26
Q

What two scientists made important discoveries related to the speed of light?

A
  1. Ole Romer: made the first reasonably accurate measurement of the speed of light.
  2. Albert A Michelson: refined Romer’s measurement by placing two mirrors on the top of two mountain peaks. He they calculated how long it took for the light to travel that distance.
    - He calculated the speed of light to be 299 798km/s
27
Q

What is the difference between converging and diverging?

A

Converging means that light is coming together or intersecting (usually at the focal point).

Diverging means that light rays are moving apart or further away from each other.

28
Q

Refraction occurs because of changes in the ___________.

A

Speed of light.

29
Q

The more dense the medium, the slower light will travel and the less it will refract.

True or False?

A

False.

While more dense materials will slow light down, this will cause the incident ray to refract MORE not less.

30
Q

What causes a mirage?

A

A mirage is an optical illusion that is caused by the variance in the refractive indexes between hot air and cold air.

Usually hot air rises and cold air falls due to convection, however in the case of a mirage Hot air remains near the warm ground, and the air above is actually colder. This causes an optical illusion to occur becuase the light refracts as it passes through the change in air density.

31
Q

If I move an image further from a CONCAVE MIRROR’s focal point what happens to the image?

A

The image will be upside down and smaller.

32
Q

If I place an image ON the focal point of a CONCAVE mirror, what will happen to the image?

A

The image will be upside down (remains the same size also).

33
Q

If an image is placed BETWEEN the focal point and a CONCAVE mirror, what will occur?

A

The image will appear upright and enlarged on the mirror.

34
Q

Does a convex mirror converge or diverge incoming light rays?

A

Diverge

35
Q

Does a concave mirror converge or diverge incoming light rays/

A

Converge

36
Q

Does a convex lense converge or diverge incoming light rays?

A

Converge

37
Q

Does a concave lense converge or diverge incoming light rays?

A

Diverge