Section 2 - Electromagnetic Spectrum and light

Question 1

What type of wave are Electromagnetic waves?

Answer 1

Transverse

Question 2

What happens when you increase the frequency of an electromagnetic wave?

Answer 2

You increase the energy transferred

Question 3

List the electromagnetic waves

Answer 3

Radio Waves
Micro Waves
Infra Red
Visible Light
Ultra Violet
X-Rays
Gamma Rays

Question 4

What does red and green light make?

Answer 4

Yellow light

Question 5

What does red and blue light make?

Answer 5

Magenta

Question 6

What does blue and green light make?

Answer 6

Cyan

Question 7

What do filters do?

Answer 7

Let through some colours of light through, and absorb the others

Question 8

What is black?

Answer 8

The absence of colour

Question 9

What is white light?

Answer 9

All of the colours of light combined

Question 10

How do we see light?

Answer 10

By light reflecting off the object and into our eyes. The object absorbs all of the light that is not the same colour as it.

Question 11

Why do waves refract when changing medium?

Answer 11

Waves move at different speeds in materials with different densities, so when a wave changes medium it changes speed. When the wave hits the new medium at an angle, it causes a change in speed, this change of speed causes a change in direction.

Question 12

What affects how much a wave refracts?

Answer 12

The shorter the wavelength the more it refracts

Question 13

When a wave refracts and it slows down, which way does it bend?

Answer 13

Towards the normal

Question 14

When a wave refracts and it speeds up, which way does it bend?

Answer 14

Away from the normal

Question 15

What happens when a wave enters a new medium along the normal line?

Answer 15

It will change speed but will not refract

Question 16

What is a converging lense?

Answer 16

A converging lense bulges in the middle. Causing parallel rays of light to converge on a principal focus

Question 17

What is a diverging lens?

Answer 17

A diverging lens caves outwards. It causes parallel rays of light to converge outwards.

Question 19

What is the focal length of a lens?

Answer 19

The distance between the centre of the lens and the principal focus

Question 19

What affects the focal length of a lens?

Answer 19

The more powerful the lens, the shorter the focal length. Because the lens is making the rays of light converge more.

Question 20

What is the principle focus of a converging lens?

Answer 20

Where the rays hitting the lens parallel to the axis all meet

Question 21

What is the principle focus of a diverging lens?

Answer 21

The point where rays hitting the lens parallel to the axis appear

Question 22

When is a real image formed by a lens?

Answer 22

When the light rays passing through the lens come together to form the image.

Question 23

When is a virtual image formed by a lens?

Answer 23

When the light passing through the lens creates an image that appears to be in a different place than the rays are coming from. (For example the image appears smaller that it should.)