Waves

Question 1

What is Phase difference?

Answer 1

the fraction of a cycle (measured in degrees or radians) between the oscillations of two particles

Question 2

What is Path difference?

Answer 2

the difference in the distances travelled by two waves from coherent sources at a particular point

Question 3

Principle of superposition (Waves)

Answer 3

when two or more waves meet, the resultant displacement is equal to the sum of the displacements of each wave

Question 4

Interference

Answer 4

when two waves superpose at a point and there is a change in overall displacement

Question 5

Displacement

Answer 5

distance moved from equilibrium of a point on a wave

Question 6

Amplitude

Answer 6

maximum displacement

Question 7

Wavelength

Answer 7

the distance between two adjacent peaks ‘or’ troughs

Question 8

Period

Answer 8

the time taken for one complete oscillation of a particle

Question 9

Frequency

Answer 9

number of wavelengths passing a point per unit time

Question 10

Plane polarized wave

Answer 10

a transverse wave that vibrates in one plane only

Question 11

Node

Answer 11

A point on a stationary wave where the amplitude is always zero

Question 12

Antinode

Answer 12

A point where the amplitude of the standing wave takes the maximum possible value

Question 13

Coherence

Answer 13

Same frequency and constant phase difference

Question 14

Monochromatic

Answer 14

Same wavelength

Question 15

What are the condition required for a stationary wave to form?

Answer 15

Two waves travelling/propagating in opposite directions superpose with the same frequency and similar amplitudes

Question 16

What is an antinode on a stationary wave?

Answer 16

A point where the progressive waves are in phase and constructively interfering resulting in maximum amplitude

Question 17

What is an node on a stationary wave?

Answer 17

A point where the progressive waves are in antiphase and are destructively interfering resulting in minimum amplitude

Question 18

How many wavelengths are there between adjacent nodes of a standing wave?

Answer 18

Half a wavelength

Question 19

What is the phase difference between points either side of a node?

Answer 19

Pi Rad/180 degrees

Question 20

What is the phase difference of points between two adjacent nodes?

Answer 20

Zero

Question 21

How does phase vary along a progressive wave?

Answer 21

Changes continuously across each wave cycle.

Question 22

How does amplitude vary in a stationary wave?

Answer 22

It varies continuously along the wave. It is a maximum at antinodes and a minimum at nodes

Question 23

How does amplitude vary in a progressive wave?

Answer 23

It is the same at every point along the wave.

Question 24

What type of wave doesn’t tranfer energy?

Answer 24

Stationary waves

Question 25

What is the fundamental frequency of a string?

Answer 25

The lowest frequency which produces a stationary wave on the string.

Question 26

Why can only certain frequency stationary waves be produced on a stretched string?

Answer 26

here must be nodes at the fixed ends and only certain frequencies/wavelengths allow this.

Question 27

What is the principle of superposition in waves

Answer 27

When two waves meet at a point the resultant displacement is the (vector) sum of the displacements of the individual waves

Question 28

What is constructive interference?

Answer 28

When two waves superpose in phase causing an increase amplitude.

Question 29

What path difference is required for waves to be in phase?

Answer 29

A whole number of wavelengths

Question 30

What path difference is required for waves to be in antiphase?

Answer 30

An odd number of half wavelengths

Question 31

What is the relationship between path difference and phase difference for coherent sources?

Answer 31

(Path difference/wavelength) x 2π

Question 32

What term describes a phase difference of zero between two waves?

Answer 32

In phase

Question 33

What term describes a phase difference of π radians between two waves?

Answer 33

In antiphase

Question 34

What is x in the double slit equation (λ = ax/D)?

Answer 34

Fringe seperation

Question 35

What is D in the double slit equation (λ = ax/D)?

Answer 35

Distance between the double slits and the screen

Question 36

What is a in the double slit equation (λ = ax/D)?

Answer 36

Distance between the double slits

Question 37

What did Young's double slit experiment demonstrate about the nature of light?

Answer 37

That light exhibits wave behaviour.

Question 38

What name is given to light of a single frequency/wavelength?

Answer 38

Monochromatic