Waves

Question 1

Define amplitude

Answer 1

Maximum displacement from equilibrium position (m)

Question 2

Define period of an oscillation

Answer 2

The time taken for one oscillation (s)

Question 3

Define displacement

Answer 3

Distance form the equilibrium position in a particular direction; can have a positive or negative value (m)

Question 4

Define phase difference

Answer 4

The difference between displacement of particles along a wave

Question 5

Define frequency

Answer 5

The number of waves passing a certain point per unit time (hz)

Question 6

Define wave speed

Answer 6

The distance travelled by the wave per unit time

Question 7

What is a longitudinal wave

Answer 7

A wave where the direction of oscillation travels parallel to direction of motion. It is made up of compressions and rarefactions.

Question 8

What is a transverse wave

Answer 8

Is a wave which it is direction of oscillation is perpendicular to the direction of motion.

Question 9

What is the equation for wave speed

Answer 9

V=fλ

Question 10

Equation for frequency

Answer 10

F=1÷Period of oscillation

Question 11

Define intensity

Answer 11

The radiant power passing through a surface per unit area measured in (Wm⁻²)

Question 12

Equation for intensity

Answer 12

Intensity = power/area

Question 13

What is reflection

Answer 13

When the waves bounces back when it hits a boundary. The angle of incidence is always equal to the angle of reflection.

Question 14

What is refraction

Answer 14

The bending of light as it passes from one medium to another. The amount of refraction depends on the refractive index of the material.

Question 15

What is the equation for refractive index

Answer 15

Speed of light in vacuum/speed of light in material

N=C/V

Question 16

What is snells law

Answer 16

n₁sinθ₁=n₂sinθ₂

Question 17

Equation to find the critical angle

Answer 17

SinC=1/n

Where C is the critical angle

Question 18

What is the wavelength of radio waves

Answer 18

10⁻¹ to 10⁶

Question 19

What is the wavelength of microwaves

Answer 19

10⁻³to 10⁻¹

Question 20

What is the wavelength of infrared

Answer 20

7x10⁻⁷ to 10⁻³

Question 21

What is the wavelength of visible light

Answer 21

4x10⁻⁷ to 7x10⁻⁷

Question 22

What is the wavelength of ultraviolet

Answer 22

10⁻⁸ to 4x10⁻⁷

Question 23

What is the wavelength of x-rays

Answer 23

10⁻¹³ to 10⁻⁸

Question 24

What is the wavelength of gamma rays

Answer 24

10⁻¹⁶ to 10⁻¹⁰

Question 25

What do all electromagnetic waves have in common

Answer 25

• All travel at the speed of light
• They are all transverse waves
• They all travel through a vacuum
• They all travel in straight lines
• Electromagnetic waves with a higher frequency have higher energy while low frequency has low energy.
• They can diffract, refract, reflect

Question 26

What is polarised light and what is unpolarised light

Answer 26

Polarised light in when light oscillated in one plane of movement

Unpolarised light is when light oscillates in many different planes

Question 27

What type of waves can be polarised

Answer 27

Only transverse waves

Question 28

Describe an experiment to show polarisation

Answer 28

Have an emitter emitting an transverse waves.
Have two filters orientated the same way, there should be only one plane of movement.
As you rotate one filter the intensity will decrease and will become 0 when filters orientation are perpendicular.
You will measure intensity with a receiver.

Question 29

What is superposition

Answer 29

When two waves of the same type meet and pass through each other. Where they overlap they produce a single wave. The resultant wave will be the displacements added together.

Question 30

What is total constructive interference

Answer 30

Is when the resulting wave is twice the original wave because the two waves are completely in phase 0, 2π, 4π

Question 31

What is total destructive interference

Answer 31

Is when the resulting wave amplitude is 0 because the two waves are in anti phase π, 3π, 5π

Question 32

What is diffraction

Answer 32

The spreading out of a wave as it passes through an aperture or obstacle

Question 33

When does greatest diffraction occur

Answer 33

λ=a greatest diffraction
λ>a notice diffraction
λ<a></a>

Question 34

Young’s double slit experiment conditions and the equation

Answer 34

• Light must be monochromatic
• Light must be coherent (constant phase difference)
• Path difference must be 1λ to make a bright fringe

λ=ax/d

Question 35

What is diffraction gratings

Answer 35

Is when you shine white light through a diffraction grating produce dark and bright fringes. However where there is a bright fringe it shows the spectrum.

Question 36

What is a stationary wave

Answer 36

A stationary wave is the superposition of two progressive waves with the same wavelength moving in opposite directions.
No energy is transmitted it is stored.

Question 37

What is a node

Answer 37

Points on the stationary wave at which there is no amplitude of the particular at any time.

Question 38

What is an antinode

Answer 38

Points on a stationary wave of maximum amplitude

Question 39

How are stationary waves different to progressive waves

Answer 39

In stationary waves energy is stored, in progressive energy is transmitted.
In progressive waves all parts have the same amplitude but in stationary they are arm different.

Question 40

What is the first harmonic in terms of wavelength

Answer 40

It is half a wave length

Question 41

What is the first harmonic in a closed tube

Answer 41

1/4 wavelength of a stationary wave.

Question 42

How to determine the speed of sound

Answer 42

• Create a closed end pipe by placing a hollow tube in water.
• Get a tuning fork and hold it above the tube.
• Move the tube up and down until you find the shortest distance between the tube and the water level that the sound resonates the loudest.
• This would be a quarter wavelength. Find the full wavelength by multiplying the length by 4.
• Then use equation V=fλ