Light and optics quiz - 1

Pythagoras ( Greek mathematician )

Light comes from our eyes

Euclid ( Greek )

Light travels in straight lines when striking a plane mirror, the angle of reflection and the angle of incidence is equal

Ptolemy ( Greek astronomer )

How light beams bend when they go through air to glass ( refraction )

Al - Haythem ( Arab scientist )

Light bounces off objects and to our eyes

Sir Issac Newton ( English scientist )

White light is made of a mixture of different colors of light and when passing through a prism, it splits up

Albert A. Michelson ( scientist )

Calculated the speed of light by placing 2 mirrors on top of 2 mountains, measured the distance, and shone a light to 1 and the other.

Speed of light

299 798 km/s

Formula

distance / speed = time ( seconds )

or

distance / speed = j —> j / 60 = time ( minutes )

Optical devices

Any device that uses light

Refracting telescope

Lens on each end of the tube (larger = objective lens ). Gathers and focuses rays to eyepiece

Reflecting telescope

Large circular mirror that curves in ( concave mirror ) that reflects the light to a lens which then directs it to the eyepiece

Ray

Light travelling from its source in a straight line that represents the path of light

Transparent

All light can get through

Translucent

Some light can go through

Opaque

No light can go through ( reflects or absorbs )

Luminous

Produces light

Non - luminous

Doesn’t produce light

Regular reflection

Happens when rays hit a smooth surface. Reflected at the same angle ( rays are parallel )

Diffuse reflection

Happens when rays hit an uneven surface. Reflected in different angles

Concave mirror

Curves inward

• images are closer / larger

• collects light from a large area to bring it into a focal point

Between mirror and focal point

Image = upright and large

Past focal point

Image = upside down and small

Convex mirror

Bluges out

• images are smaller and further away

• focal point behind

Lens

Piece of curved glass or any other transparent material

Concave lens

Thinner in the centre than the edges

• diverges light rays

Convex lens

Curves outward and is thicker in the middle

• converges light rays

Convex lenses uses

1) acts like a light collector

• collects and focuses light

2) forms a real image

• rays meet at a point and image can be projected onto a screen