Waves

Question 0

When are longitudinal waves produced

Answer 0

When the vibrations are parallel to the axis

Question 1

What do waves transfer?

Answer 1

Energy (NOT matter)

Question 4

Compression

Answer 4

Region where the particles are closer

Question 5

A region where the particles are farther apart

Answer 5

Rarefaction

Question 6

What is the relationship between the amount of diffraction and wavelength

Answer 6

The longer the wavelength the more diffraction there is

Question 7

Why is red light diffracted the most

Answer 7

Longer wavelength

Question 8

What is the time period of a wave and what is it measured in

Answer 8

The time it takes for a source to produce one wave, measured in seconds

Question 9

What is the frequency of a wave & what is it measured in?

Answer 9

The number of waves produced each second, hertz

Question 10

What is the equation relating frequency (f) and time period (T)

Answer 10

f = 1 ➗ T
Or
T = 1➗f

Question 11

The height of a sound wave is related to

Answer 11

The volume

Question 12

The greater the amplitude..

Answer 12

The louder the sound

Question 13

The amplitude

Answer 13

The maximum displacement of the wave from the undisturbed/equilibrium position

Question 14

The number of waves produced is related to

Answer 14

The pitch or frequency

Question 15

The wave equation

Answer 15

Wave speed = frequency x wavelength

Question 16

Wavelength

Answer 16

The distance in metres from any point on the wave to where it repeats

Question 17

When are transverse waves produced

Answer 17

When the vibrations are at right angles to the direction of energy

Question 18

What is a wave

Answer 18

A vibration or disturbance transmitted through a material (a medium) or through space

Question 19

Light waves are

Answer 19

Transverse

Question 21

Shortest wavelength, highest frequency, highest energy

Answer 21

Gamma rays

Question 22

Properties that all electromagnetic waves share 2

Answer 22

Transverse waves

Can travel through a vacuum

Question 23

Longest wavelength, lowest frequency & lowest energy

Answer 23

Radio waves

Question 24

Trough

Answer 24

Point on a wave with the lowest displacement

Question 25

What is refraction

Answer 25

The bending of light when it enters a different medium

Question 26

Why does the refractive index have no units?

Answer 26

It’s a ratio

Question 27

When does TIR occur

Answer 27

When the angle of refraction is greater than 90 and the light cannot leave the medium

Question 28

What's normal?

Answer 28

An imaginary line that's at right angles to the surface (at the point where light hits the surface)

Question 29

Law of reflection

Answer 29

The angle of incidence equals the angle of reflection

Question 30

Critical angle

Answer 30

The angle of incidence above which TIR occurs

Question 31

Why do diamonds sparkle

Answer 31

Diamond has a very high refractive index and so a low critical angle which leads to more internal reflections

Question 32

Why is a semicircular block used to demonstrate total internal reflection

Answer 32

The incident ray always hits the curved side of the block at 90* so there are no refraction effects as it enters the block, only when it leaves from the straight edge

Question 33

Properties of image in plane mirror (4)

Answer 33

- laterally inverted - virtual - same size - as far behind the mirror as the object is in front

Question 34

Explain why a ray entering a glass block changes direction each time it crosses the air/glass boundary

Answer 34

As the ray of light enters the glass block, it slows down and is refracted towards the normal. As the Ray leaves the glass block, its speed increases and it is refracted away from the normal

Question 35

Why is white light dispersed

Answer 35

White light is composed of a mixture of colours. Because each colour travels at a different speed through the prism, they are refracted through different angles

Question 36

Advantage of using prisms in a periscope rather than plane mirrors

Answer 36

The final image created by a prismatic periscope is likely to be sharper and brighter

Question 37

What would happen to a ray of light inside an optical fibre if the outer glass had a higher optical density than the inner glass?

Answer 37

If the outer glass of an optical fibre had a higher refractive index, light within the fibre striking the boundary would be refracted and escape through the sides

Question 38

Médical application of optical fibres

Answer 38

Endoscopes allow doctors to see inside the body, and make keyhole surgery possible