Waves

Question 1

What are all sounds cause by?

Answer 1

A vibrating object

Question 2

What is the amplitude of a wave?

Answer 2

The amplitude of a sound is how loud it is. The amplitude is the distance from the line of 0 disturbance to the top of the wave

Question 3

What happens to a wave trace when the amplitude is increased?

Answer 3

The waves will get taller and sound louder

Question 4

What happens to a wave trace when the amplitude is decreased?

Answer 4

The waves will get smaller and will sound quieter

Question 5

What is the frequency of a wave?

Answer 5

The frequency of a wave is its pitch. A high note = high pitch and a low note = low pitch

Question 6

What happens to a wave trace when the frequency is increased?

Answer 6

More waves will appear in the period of time and the sound will be higher pitched

Question 7

What happens to a wave trace when the frequency is decreased?

Answer 7

Less waves will appear in the period of time and the sound will be lower pitched

Question 8

What is the frequency of human hearing?

Answer 8

20Hz-20,000Hz

Question 9

When a sound is below 20Hz or above 20,000Hz what happens?

Answer 9

It becomes inaudible to humans

Question 10

What is refraction?

Answer 10

Refraction is the change of speed which occurs when light travels from one optical medium to another

Question 11

What happens to light when it undergoes refraction?

Answer 11

When light undergoes refraction it need not change direction, it will change speed and bend towards the normal

Question 12

What is the normal?

Answer 12

The normal is an imaginary line perpendicular to the surface at which light enters the Perspex

Question 13

What is the angle of refraction?

Answer 13

The angle of refraction is measured between the refracted ray and the normal

Question 14

What is the angle of incidence?

Answer 14

The angle of incidence is measure between the incident ray and the normal

Question 15

What happens when light passes through the Perspex?

Answer 15

The light will pass through in 1 beam in an undisturbed line. When the incident ray passes into 90° to the normal it does not change path

Question 16

Describe how a converging lens focuses light

Answer 16

A converging lens bends the light into one focal point and back out to form a clear image

Question 17

Describe how a diverging lens focuses light

Answer 17

A diverging lens bends light away causing you to look for a virtual focal point. The virtual focal point is where the rays have come from so the focal length is negative

Question 18

How does an image appear when produced by a converging lens?

Answer 18

It will appear diminished, horizontally flipped and vertically flipped

Question 19

What is the equation for measuring the optical power of a lens?

Answer 19

Optical Power= 1/Focal length
Or…
P=1/F

Question 20

How do you measure the focal length of a converging lens?

Answer 20

F=1/P

Question 21

Thicker lenses have a greater what, than a thinner lens?

Answer 21

Lenses with greater curvature have a higher optical power

Question 22

What is the relationship between optical power and focal length?

Answer 22

P=1/F

Question 23

What is the optical power measured in?

Answer 23

Diopters (D)

Question 24

What is the focal length measured in?

Answer 24

Meters (m)

Question 25

What is the function of the cornea?

Answer 25

Transparent outer lens which does most of the eyes refraction

Question 26

What is the function of the lens?

Answer 26

Focuses light onto the retina. Changes thickness to vary the amount of refraction

Question 27

What is the function of the pupil?

Answer 27

An aperture (hike) which allows light in, it changes size according to how bright it is

Question 28

What is the function of the retina?

Answer 28

The light sensitive coating at the back of your eye. Retina cells change light energy into electrical signals sent to the brain

Question 29

What is the function of the optic nerve?

Answer 29

Takes electrical signals from the retina to the brain

Question 30

What effect does light have on the pupil of the eye?

Answer 30

In brighter conditions the pupil shrinks as the eye can only take in so much light at a time therefore when a lot of light is present it can’t take it in therefore shrinks. When the light is dim the pupil grows so it can take in as much light as possible

Question 31

What causes the blind spot in the eye and what effect does it have on your vision?

Answer 31

There is a point in the retina at which the optic nerve is connected cannot detect light because there are no light sensitive cells this is your blind spot. Light from an object landing on your blind spot cannot be seen

Question 32

What happens to the image formed by a converging lens when the object is brought closer?

Answer 32

When the object is moved closer the image gets bigger

Question 33

How does the eye accommodate to distant and near objects?

Answer 33

If the object is near to the eye the lens will thicken and if the object is far away the lens will become thinner and relax

Question 34

What is meant by accommodation of the eye?

Answer 34

The eye accommodates it’s lens thickness based on how near or far an object is

Question 35

Describe the nature of rays of light coming from a distant object

Answer 35

When rays of light come from a distant object they will come together in parallel to form a focal point and then back out

Question 36

Describe that nature of rays of light coming from a near object

Answer 36

The rays of light coming from a near object will