Waves

Question 1

wavefront

Answer 1

A line of points in phase with each other in a wave, perpendicular to the direction of energy transfer

Question 2

Radio

Answer 2

-1 to 6m

Question 3

Infrared

Answer 3

-3 to 7x-7

Question 4

Visible

Answer 4

7x-7 to 4x-7m

Question 5

Ultraviolet

Answer 5

4x-7 to -8m

Question 6

X-rays

Answer 6

-8 to -10m

Question 7

Gamma

Answer 7

-10 to -16m

Question 8

Wave Speed

Answer 8

the distance travelled by a wave per unit time

Question 9

Frequency

Answer 9

the number of complete wavelengths passing a given point per unit time

Question 10

Period

Answer 10

the time taken for a full oscillation of one wavelength to pass a given point

Question 11

Wavelength

Answer 11

the minimum distance between two adjacent points on a wave oscillating in phase

Question 12

Amplitude

Answer 12

the maximum displacement from the origin

Question 13

displacement

Answer 13

the distance from the equilibrium position in a particular direction

Question 14

phase difference

Answer 14

difference in displacement between two particles on a wave/different waves

Question 15

micro

Answer 15

-1 to -3m

Question 16

Principle of Superposition

Answer 16

when two waves meet at a point, the resultant displacement of the wave at that point is equal to the sum of their individual displacements.

Question 17

Node

Answer 17

A point on a standing wave that always has no displacement from the rest position

Question 18

Antinode

Answer 18

A point of maximum displacement midway between two nodes in a standing wave

Question 19

Polarised light

Answer 19

Transverse wave in plane normal to the direction of energy propagation. Oscillations in one direction are confined to a single plane.

Question 20

wave

Answer 20

the transfer or storing of energy through a medium by oscillations of the particles in that medium

Question 21

Total Internal Reflection

Answer 21

the complete reflection that takes place within a substance when the angle of incidence of light striking the surface boundary is more than the critical angle

Question 22

Speed of light in water

Answer 22

2.25 x 10^8 m/s

Question 23

Refractive Index Glass

Answer 23

1.5

Question 24

Refractive Index Water

Answer 24

1.3

Question 25

Polaroids

Answer 25

transparent polymers. long chain molecules that absorb molecules

Question 26

Polarisation

Answer 26

Oscillations of a transverse wave are limited to only one plane

Question 27

Refraction

Answer 27

A wave changes direction as it changes speed, when it enters a new medium. partial reflection occurs.

Question 28

Reflection

Answer 28

A wave changes direction at a boundary between two media, remaining in the original medium.

Question 29

Diffraction

Answer 29

The spreading out of a wave front as it passes through a gap or around an obstacle.

Question 30

Intensity

Answer 30

The radiant power passing at right angles through a surface per unit area

Question 31

Similarity between progressive/standing waves

Answer 31

Both have frequency/wavelength/period

Question 32

2 differences between standing and progressive

Answer 32

Adjacent particles have same max. amplitude on progressive, different amplitudes on standing. Progressive waves transport energy from source to absorber, standing waves store energy.

Question 33

Electron circles

Answer 33

Diameter of circle is proportional to wavelength of electron

Question 34

Intensity definition

Answer 34

the rate of flow of energy per unit area at right angles to direction of travel of wave.

Question 35

What are the 6 different wave phenomena?

Answer 35

Reflection, refraction, polarisation, diffraction, superposition, interference

Question 36

How would you change wave speed in a wave tank?

Answer 36

Change depth of water.

Question 37

How do sunglasses reduce glare?

Answer 37

reflected light from surface is partially plane polarised polarising sheet is placed at right angles to reflected light plane

Question 38

What does 'in phase' mean?

Answer 38

Two points are in phase if they are at the same point in a wave cycle.

Question 39

Coherence definition

Answer 39

Two waves are coherent if they have the same wavelength, frequency and fixed phase difference

Question 40

What is the path difference?

Answer 40

The length of one wave's path minus the length of the other wave's path.

Question 41

What is the path difference for constructive interference?

Answer 41

nλ

Question 42

What is the path difference for constructive interference?

Answer 42

nλ

Question 43

Interference definition

Answer 43

When two or more waves superpose and there is an overall change in displacement.

Question 44

Why do we use more slits?

Answer 44

Maxima get brighter and narrower, minima get dimmer, more precise measurements

Question 45

What happens if you use white light instead of a monochromatic light source in a diffraction experiment?

Answer 45

Central white fringe, maxima become spectra, because different wavelengths in white light are diffracted different amounts.

Question 46

What is a stationary wave?

Answer 46

The superposition of two progressive waves with the same wavelength, moving in opposite directions.

Question 47

How to test whether waves are plane polarised?

Answer 47

Take polaroid/metal grille and rotate it in front of transmitter with detector behind. If reading of 0 occurs, then they are plane polarised.