Waves

Question 1

What is amplitude?

Answer 1

The displacement from the rest to the crest

Question 2

What is wavelength?

Answer 2

The length of a full cycle (crest to crest)

Question 3

What is frequency?

Answer 3

The number of complete waves produced per second

Question 4

What does Hz mean?

Answer 4

Wave per second

Question 5

If the angle of reflection is 50 degrees, what is the size of the angle of incidence?

Answer 5

50 degrees

Question 6

Where is the normal?

Answer 6

A 90 degree angle from the surface of the mirror

Question 7

What makes an image virtual?

Answer 7

When it appears to be somewhere (behind the mirror) but in reality, is not

Question 8

What are transverse waves?

Answer 8

Vibrations perpendicular to the energy transfer of the wave (e.g. Light, EM waves, ripples)

Question 9

What are longitudinal waves?

Answer 9

Vibrations parallel to the direction of energy transfer

Question 10

How do you find frequency? (Hz)

Answer 10

Speed (m/s) / wavelength (m)

Question 11

What is diffraction?

Answer 11

When waves spread out at the edges when they pass an obstacle

Question 12

What causes a wave to greatly diffract?

Answer 12

A narrow gap or a long wavelength

Question 13

What happens if the gap and the wavelength are the same size?

Answer 13

The wave fully diffracts

Question 14

How does refraction work?

Answer 14

The wave passes through a medium denser than air and slows down, changing direction

Question 15

What happens if the waves meet the medium along the normal?

Answer 15

They slow down but do not refract

Question 16

What is the range of EM wave size?

Answer 16

10^-15 - 10^4

Question 17

____ frequency, ____ wavelength

Answer 17

Higher frequency, shorter wavelength

Question 18

Radio waves diffract. What does this make them useful for?

Answer 18

Sending waves around the world or obstacles by bouncing them off the Earth’s curved surface

Question 19

Mnemonics for remembering the electromagnetic spectrum

Answer 19

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Question 20

Why are microwaves good for satellite communication and mobile phones?

Answer 20

They can easily pass through the Earth’s atmosphere

Question 21

What is an echo?

Answer 21

A reflected sound wave

Question 22

How do you find wave speed?

Answer 22

Frequency * wavelength

(V = f*λ) [lambda]

Question 23

What is a mechanical wave?

Answer 23

One that must travel through a medium

Question 24

What is an electromagnetic wave?

Answer 24

One that doesn’t need to travel through a medium

Question 25

Uses of radio waves

Answer 25

Television

Radio

Mobile phones

Bluetooth

Question 25

Uses of micro waves

Answer 25

Cooking

Mobile phone calls

Satellite dishes

Question 26

Uses of infrared waves

Answer 26

Optical fibre communications

Toasters

Heaters

Grills

Question 27

Uses of light waves

Answer 27

Fibre optic cables

Digital cameras

Question 28

Which wave may be used to send a signal to a satellite through the ionosphere?

Answer 28

Microwave

Question 29

What will happen to the frequency, wavelength and speed of a reflected microwave?

Answer 29

Wavelength - decrease

Frequency - increase

Speed - same