Revision 2

Question 1

What are transverse waves?

Answer 1

Transverse waves vibrate at 90° to the direction of energy transfer
E.g all electromagnetic waves

Question 2

What are longitudinal waves?

Answer 2

Longitudinal waves vibrate parallel to the direction of every transfer.
E.g sound sound waves
The vibrations are known as compressions and rarefactions

Question 3

Mechanical waves

Answer 3

Mechanical waves which need a medium to travel through may be transverse or longitudinal
E.g waves on a slinky Spring

Question 4

Amplitude

Answer 4

The amplitude of a wave is the height of the wave crest from the position of rest.

Question 5

Frequency

Answer 5

The frequency of a wave is the number of wave crests passing a point in one second
Unit : hertz

Question 6

Wavelength

Answer 6

The wavelength of a wave is the distance from one wave crest to another.

Question 7

The wave equation

Answer 7

Speed(m/s)= frequency(Hz) x wavelength(m)

Question 8

Transparent

Answer 8

Objects that are transparent transmits all light.

Question 9

Translucent

Answer 9

Transmits some light

Question 10

Opaque

Answer 10

Objects which don’t transmit light are said to be opaque.

Question 11

Why are shadows opaque?

Answer 11

Light rays travel in straight lines. This is why the shadows of opaque objects are very well defined.

Question 12

How is the normal line drawn?

Answer 12

The normal line is a line drawn perpendicular to the mirror.

Question 13

What are waves used for?

Answer 13

Waves are used to transfer energy and information.

Question 14

Light Ray reflected by a plane mirror

Answer 14

The angle of incidence = the angle of reflection

The angle of incidence = the angle between the incident Ray and the normal

Question 15

Real image

Answer 15

A real image can be projected onto a screen.

Question 16

Virtual image

Answer 16

A virtual image only exists in the mirror.

Question 17

In a plane (flat) mirror, the image is _____, virtual and the same size as the object.

Answer 17

Upright

Question 18

Reflection from a ____ surface in a single direction is called _______ reflection

Answer 18

1. Smooth

2. Specular

Question 19

Reflection from a ______surface causes______ .This is called _____reflection.

Answer 19

1. rough
2. Scattering
3. diffuse

Question 20

White light contains ___ the colours of the visible spectrum

Answer 20

All

Question 21

The colour of an object depends on the colour that it____ and the colour that it____.

Answer 21

1. reflects

2. absorbs

Question 22

The three primary colours

Answer 22

Red,green and blue

Question 23

Combining two of the primary colours creates a________colour.

Answer 23

Secondary

Question 24

A coloured filter allows some colours to pass through it and absorbs the rest. We see the colour that the filter______.

Answer 24

Transmits

Question 25

Refraction is the_____________ of waves when they travel across a boundary. This change in direction is due to a_______.

Answer 25

1. Change in direction | 2. Change in speed

Question 26

When light passes__________ the angle of refraction(in the glass) is___ than the angle of incidence

Answer 26

1. form air into glass | 2. less

Question 27

Diffraction is the________of waves when they pass through a gap or round an obstacle.

Answer 27

Spreading out

Question 28

The________the gap, the greater the diffraction

Answer 28

Narrower

Question 29

The gap must be a_____ _____ to the wavelength of the wave in order for diffraction to take place. This why light cannot diffract round an open doorway but sound can.

Answer 29

Similar size

Question 30

If radio waves ___ ______ _____ when they go over hills, radio and TV reception will be poor.

Answer 30

Do not diffract enough

Question 31

The frequency range of the normal human ear is from about____ to_____.

Answer 31

1. 20Hz | 2. 20 000Hz

Question 32

Sound waves are vibrations that travel through a_____(substance). They cannot travel through a_______.

Answer 32

1. Medium | 2. Vacuum

Question 33

Echoes are due to sound waves______from a hard,smooth surface

Answer 33

Reflected

Question 34

Refraction takes place at the boundaries between layers of air at_______ _________. The warmer the air the_______ the speed of sound.

Answer 34

1. different 2. temperatures 3. greater

Question 35

At night you can hear sound a long way away from its source because sound waves______ _______to the ground.

Answer 35

Refract back

Question 36

The______of a note increases if the frequency of the sound waves increases.

Answer 36

Pitch

Question 37

The loudness of a note increases if the_________of the sound waves increases

Answer 37

Amplitude

Question 38

A microphone converts______ _____ to an_______ _______. This can be displayed on an oscilloscope.

Answer 38

1. sound waves | 2. electrical signal