Light and Sound

Question 1

What do all waves transfer

Answer 1

Energy + Information

Question 2

Give some properties of light waves

Answer 2

Transverse
Energy is perpendicular yo the direction of the movement
Speed of light
Transfer energy

Question 3

What is the law of reflection

Answer 3

The angle of incidence = the angle of reflection

Question 4

What is the name given to the type of image formed in the mirror

Answer 4

The Virtual

Question 5

A material which light passes through, such as glass or air, is known as….

Answer 5

A medium

Question 6

When light waves travel into a denser medium, they bend…….the…….., this is because they……down

Answer 6

Towards
Normal
Slow

Question 7

What happens when light leaves a denser medium, into air

Answer 7

It bends away from the normal

Question 8

How fast does light travel in a vacuum

Answer 8

3x100000000 (to the 8)

Question 9

Refractive Index is the measure of how much a substance…..light. The……the value, the more a medium slows light

Answer 9

Slows

Higher

Question 10

Give the equation that links the refractive index, angle (i) and angle (r)

Answer 10

Sin (i) = Refractive Index x Sin (r)

Question 11

Give two conditions for Total Internal Reflection to occur

Answer 11

The angle of incidence must be greater than the critical angle

The light must be passing from a high refractive index to a low one (from a dense medium to a less dense one)

Question 12

What is the critical angle

Answer 12

Is the angle of incidence when the angle of of refraction is 90º

Question 13

What does the symbol n mean

Answer 13

Refractive Index

Question 14

What are optical fibres

Answer 14

Used in telecommunications and the endoscope (for looking inside the body, without cutting)

Question 15

What is Total Internal Reflection

Answer 15

When a light ray INSIDE a DENSE object hits a surface, if the angle (i) is greater than the critical angle, Total Internal Reflection occurs

Question 16

What are digital signals made up of

Answer 16

1 or 0 (on or off)

Question 17

What are analogue signals

Answer 17

Consist of a continuous waveform which can have any value (of amplitude or frequency)

Question 18

Amplifying an analogue signal also amplifies the…..

Answer 18

Noise

Question 19

Are sound waves longitudinal or transverse waves

Answer 19

Longitudinal

Question 20

Can sound travels through a vacuum

Answer 20

No

Question 21

What is Diffraction

Answer 21

The spreading that occurs when a wave passes an edge or goes through a gap

Question 22

In Diffraction, what happens if the wavelength is smaller than the gap

Answer 22

Very little diffraction occurs, so the waves pass straight through without spreading

Question 23

In Diffraction, what happens if the wavelength and the gap are the same

Answer 23

Maximum diffraction occurs

Question 24

Give an example when Diffraction is present

Answer 24

When sound waves leave a speaker

Sound waves pass through a doorway

Question 25

Give the equation that links frequency and time

Answer 25

Frequency = 1/time

Question 26

Describe a method to measure the speed of sound

Answer 26

Get a distance of 150m using a trundle wheel.

Get 1 person on one end and the rest on the other side

The group of people each have a signal

When the 1 person lowers his arm, he shoots a (blanc) gun.

Everyone then uses the stopwatch from when he lowers his arm to when they here the sound.

Repeat this 4 times.

Do the equation of 150 x average result
= speed of sound

Question 27

Give the equation that links the Critical angle and the Refractive Index

Answer 27

Sin (C) = 1/n