Phase Difference

Question 1

What is phase difference?

Answer 1

The separation of two points on a wave as a fraction of the wavelength expressed as an angle in radians

Question 2

What can be said about the energy transferred to the wave?

Answer 2

Energy is directly proportional to the amplitude

Question 3

What happens to the depth as amplitude is increased?

Answer 3

Depth increases

Question 4

How can a value of k be determined?

Answer 4

Experimentally only

Question 5

What are travelling waves?

Answer 5

Waves that oscillate as well as travel forward

Question 6

When are stationary waves formed?

Answer 6

When a reflected travelling wave overlaps the original wave and produces a waveform that looks ‘stationary’ (superposition)

Question 7

What is the disturbance?

Answer 7

The height of the combined wave

Question 8

What are coherent waves?

Answer 8

Waves with a constant phase difference

Question 9

What is perfectly constructive interference?

Answer 9

When there is a phase difference of a whole multiple number of 2 pi

Question 10

What is physically happening to the waves in perfectly constructive interference?

Answer 10

Peak meets peak and trough meets trough

Question 11

What happens in perfectly destructive interference?

Answer 11

There is a phase difference of (n+1/2)x2pi

Question 12

What physically happens when there is perfectly destructive interference?

Answer 12

Peak meets trough and trough meets peak

Question 13

What is the amplitude of a wave that has undergone perfect constructive interference?

Answer 13

The amplitude of the combined wave is 2A

Question 14

What is the amplitude of a wave that has undergone perfectly destructive interference?

Answer 14

Amplitude of combined wave 0m

Question 15

What are nodes and anti nodes on a stationary wave diagram?

Answer 15

Nodes are on the outside of the wave

Antinode is the distance between the peak and trough

Question 16

What is the first harmonic also known as?

Answer 16

The fundamental

Question 17

What kind of waves have to be used for an interference pattern to be produced?

Answer 17

Two or more coherent waves

Question 18

What is the equation for the path difference for constructive interference?

Answer 18

PD= n(wavelength)

Question 19

What is the equation to find is used to find the path difference for destructive interference(minima)?

Answer 19

PD=(n+1/2)(wavelength)

Question 20

What does D stand for?

Answer 20

Distance between the slits and screen

Question 21

What does d stand for?

Answer 21

Separation distance of the slits

Question 22

What is produced if both waves used are coherent?

Answer 22

A maxima

Question 23

How can the optical path difference be found?

Answer 23

Optical path difference(OP)=geometric path difference(GP) x refractive index (n)

Question 24

What is the path difference when the two rays are exactly the same length?

Answer 24

0

Question 25

How can optical path difference be calculated?

Answer 25

OPD=GP x n

Question 26

What equation is used to calculate OPD at a minima?

Answer 26

OPD=(m+1/2) x wavelength

Question 27

What is the equation used to calculate the OPD at a maxima?

Answer 27

OPD=m x wavelength