Waves

Question 1

What are the equations for power

Answer 1

P=IV, P=I^2R, P=E/t, P=V^2/R

Question 2

What are the units of Young’s Modulus

Answer 2

Pascals

Question 3

What are waves

Answer 3

Vibrations and oscillations that pass through space, transferring energy and information from one location to another

Question 4

What are the waves called that require a medium

Answer 4

Mechanical Waves

Question 5

When waves travel through a medium, the particles might move but they ___-

Answer 5

Dont travel with energy

Question 6

Do EM waves require a medium

Answer 6

No

Question 7

What are EM waves

Answer 7

Electromagnetic waves that are field vibrations

Question 8

What are the two types of waves

Answer 8

Transverse and longitudinal

Question 9

In what direction do transverse waves oscilate

Answer 9

Perpendicular to the direction of energy transfer

Question 10

In what direction do longitudinal waves oscillate in

Answer 10

Parallel

Question 11

What are different examples of Transverse waves

Answer 11

EM waves, S waves

Question 12

What are examples of Longitudinal waves

Answer 12

Sound waves, compression waves, P waves

Question 13

If you were to draw transverse waves, what would it look like

Answer 13

Like a Squiggly line, like you were to draw any wave

Question 14

If you were to draw a longitudinal wave what would it look like

Answer 14

A lot of lines compressing and decompressing

Question 15

What is an Amplitude

Answer 15

From the middle, to peak or trough

Question 16

What is a wavelength

Answer 16

The distance between two peaks or two identical places.

Question 17

What is the period of the wave

Answer 17

The time taken for one full wavelength

Question 18

What is wavespeed

Answer 18

The speed at which energy is transferred

Question 19

What is the unit for strain

Answer 19

Lol there is none

Question 20

When can you use SUVAT equations

Answer 20

When acceleration is constant

Question 21

What is a polarised wave

Answer 21

When a transverse wave where only the waves that can pass through are in one direction

Question 22

If a wave gets polarised twice in two different 90* angles, what happens

Answer 22

The wave disappears completely as it as been polarised

Question 23

What does Phase describe

Answer 23

The fraction of a wave cycle compared to the start of the cycle

Question 24

Does frequency change as a particle oscillates

Answer 24

No

Question 25

What does it mean for a wave to be in phase

Answer 25

They are the same frequency and at the same point in their cycle

Question 26

If waves are not exactly in phase, then what are they called

Answer 26

Out of Phase

Question 27

If waves are completely out of phase and opposite, what is that called

Answer 27

Antiphase

Question 28

What is phase difference

Answer 28

The difference of the two positions of waves, can be given as an angle where one cycle is 2π or 360*

Question 29

When two waves are antiphase what is the phase difference

Answer 29

180*

Question 30

What is diffraction

Answer 30

it was when a wave passes through a slit and spreads out in a circular type of motion

Question 31

What is the best separation of a slit for diffraction to happen

Answer 31

Approximately the wavelength of the wave

Question 32

Why is it possible to hear around a corner but not see around the corner

Answer 32

The gap of the obstacle isn't small enough for a light wave to bend around, but is big enough for a sound wave

Question 33

What is the principle of super position

Answer 33

The vector sum of two waves passing through each other will equal to the algebraic sum of the big wave

Question 34

What is constructive interference

Answer 34

When two waves are travelling, their amplitude is both positive and it gets added, and resultant wave is large

Question 35

What is destructive interference

Answer 35

When two waves travel toward each other with opposing phases, their amplitudes get added and therefore will cancel as one is negative and one is positive, effectively destroying the wave

Question 36

What are coherent waves

Answer 36

Waves that have the same frequency and a constant phase difference

Question 37

What is path difference

Answer 37

The difference in length that wave has already travelled

Question 38

What is the equation for path difference

Answer 38

Lambda = ay/D

Question 39

What does each part of Lambda = ay/D mean

Answer 39

Lambda = Wavelength a = Aperture separation y = Fringe Width D = Distance to screen

Question 40

What is the pattern for single slit diffraction

Answer 40

There is a bright central fringe, with the highest intensity of light because shortest path difference Double the size of the other bright spots

Question 41

What is refraction

Answer 41

The waves slow down or speed up when entering a different medium because the refractive index changes

Question 42

What is the requirement for Young's Double Slit equation to work

Answer 42

The light must be coherent

Question 43

What is a diffraction grating

Answer 43

When parallel slits are spaced very close to eachother

Question 44

Do Diffraction gratings produce an interference pattern over a wider or smaller area

Answer 44

Wider

Question 45

Where is 0th order on the diffraction grating pattern

Answer 45

Straight forward infront of the raybox

Question 46

What does the angle of diffraction refer to

Answer 46

The angle between consecutive diffraction beams

Question 47

How can the angle of diffraction be increased

Answer 47

Using a longer wavelength Using a grating with narrower spaced slits

Question 48

What is the diffraction grating equation

Answer 48

nλ = dsinθ where N is the beam order and d is the grating slit spacing

Question 49

What do you do to calculate n in nλ = dsinθ

Answer 49

n = 1/d where d is the grating spacing

Question 50

To find the maximum amount of orders in a diffraction

Answer 50

in nλ = dsinθ you make theta 90 and then rearrange to give you n

Question 51

How are standing waves created

Answer 51

When two travelling waves of equal frequency and ampliutde moving in opposite directions meet.

Question 52

What is the name of the 0th Harmonic

Answer 52

Fundamental

Question 53

How do you calculate the wavelength of each harmonic

Answer 53

You do: 2/which harmonic youre in L

Question 54

If you're in the 5th harmonic, what is the wavelength

Answer 54

2/5L

Question 55

What is a node

Answer 55

When two waves meet in a tube

Question 56

What in an antinode

Answer 56

When two waves in a tube are in opposite places

Question 57

In a closed tube, what is always at the end of it

Answer 57

A Node

Question 58

How do you make a standing wave

Answer 58

Get a string and apply tension Get a vibration generator Vary frequency tension or length until the wave appears

Question 59

Why is there a Node at the end of a closed tube

Answer 59

Air cannot move so there is a node

Question 60

How do you calculate refractive index

Answer 60

Refractive index = Speed of light / speed of light in vacuum

Question 61

When light enters a medium with a higher refractive index, it bends _________ the normal

Answer 61

TOWARDS

Question 62

When light enters a medium with a lower optical density, it bends ________ the normal

Answer 62

Away from

Question 63

What is a different way of saying Refractive Index

Answer 63

Optical Density

Question 64

What are the 4 things that can happen to light when it cresses into a medium with a different refractive index

Answer 64

Reflect, Refract, Absorb, Transmit

Question 65

If n2>n1, then a weak reflected ray is produced inside the medium, what is n2

Answer 65

90*

Question 66

What is TIR

Answer 66

Total internal reflection

Question 67

What is the equation of TIR

Answer 67

n1/n2 = sin(r)/sin(i)

Question 68

How to find the sin of critical angle

Answer 68

sin(r)/sin(i)

Question 69

How to find critical angle

Answer 69

sin(r)/sin(i) = sinθc sinθc = n1/n2

Question 70

what do we use TIR for

Answer 70

To keep light inside of a Fibre Optic cable. We want the angle to be as small as possible so it can never get out

Question 71

What are optical fibres

Answer 71

Long threads of glass that use TIR to send signals made of light

Question 72

What are optical fibers most used for

Answer 72

Looking inside tough spots to get into to help Data transmission

Question 73

What does each optical fibre have

Answer 73

A core and a cladding both made of glass

Question 74

Why are optical fibres not necessarily the best for long distance travel

Answer 74

The light is shone and some may go straight down the tube and therefore taking the least time, and some get reflected a lot taking a lot more time

Question 75

How do we prevent light from being diffracted a lot of time over long distances

Answer 75

Make the core thinner and cladding thicker so that everything will arrive close to the same time. Its to remove path difference

Question 76

Why do we prevent light from being diffracted a lot of time over long distances

Answer 76

To reduce path difference

Question 77

What gets refracted at higher angles, Red or Blue light

Answer 77

Red

Question 78

Can polarization happen in Longitudinal waves

Answer 78

No, only transverse

Question 79

How can you completely block all waves with 2 filters

Answer 79

Make them perpendicular to each other

Question 80

What are the uses for polarised filters

Answer 80

Fishing glassses, Camera Filter, Driving glasses