Waves

Question 1

amplitude (A) Wave

Answer 1

maximum displacement of the medium from the equilibrium position

Question 2

Amplitude (Xo) SHM

Answer 2

maximum displacement from the equilibrium position

Question 3

analyser

Answer 3

a device that can detect polarised light

Question 4

antinode

Answer 4

position of maximum displacement

Question 5

Brewster’s law

Answer 5

when light reflects off a surface it will be 100 percent polarised in the plane of the surface if angle between the reflected and refracted is 90 degree

Question 6

coherent

Answer 6

wave sources that have a fixed phase relationship

Question 7

compression

Answer 7

part of a longitudinal wave where the particles are closest together

Question 8

constructive inferencce

Answer 8

occurs when waves meet in phase to give maximum displacement

Question 9

critical angle

Answer 9

angle of incidence above which total internal reflection may occur

Question 10

destruction interference

Answer 10

occur when waves meet out of phase to give zero displacement

Question 11

diffraction

Answer 11

spreading out of waves past an obstacle or through a gap

Question 12

displacement (x) SHM

Answer 12

instantaneous distance from the equilibrium position in a specific direction

Question 13

displacement (x) wave

Answer 13

instantaneous distance from the equilibrium position in a specific direction

Question 14

electromagnetic waves

Answer 14

do not require a medium so can travel through a vacuum

Question 15

frequency (f) SHM

Answer 15

number of oscillations per second

Question 16

frequency (f) wave

Answer 16

number of oscillations of the medium per second

Question 17

fundamental frequency (fo)

Answer 17

the lowest frequency standing wave that can be formed in a pipe or on a string

Question 18

intensity (I)

Answer 18

power per unit area received by an observer

Question 19

isochronous oscillation

Answer 19

an oscillation with a constant time period

Question 20

Malus’s law

Answer 20

I = Io cos2 θ

Question 21

mechanical waves

Answer 21

requires a medium through which to travel

Question 22

node

Answer 22

position of zero displacement

Question 23

optically active substance

Answer 23

substance that rotates the plane of polarised light as light passes through it

Question 24

period (T) SHM

Answer 24

time for one oscillation

Question 25

period (T) wave

Answer 25

time for one complete oscillation of the medium (or for a complete wave to pass a given point)

Question 26

polarised light

Answer 26

light in which the electric field vector is oscillating on one plane only

Question 27

rarefaction

Answer 27

part of a longitudinal wave where the particles are furthest apart

Question 28

ray

Answer 28

shows the direction of energy transfer of a wave

Question 29

refraction

Answer 29

the change in speed of a wave that occurs when it travels into a different medium

Question 30

refractive index (n)

Answer 30

a measure of how fast a wave travels in a medium

Question 31

restoring force SHM

Answer 31

a force that is always directed towards the equilibrium position

Question 32

simple harmonic motion

Answer 32

an oscillation when the force (and acceleration) is proportional to displacement from the equilibrium position but is in the opposite direction.

Question 33

snell's law

Answer 33

n = sin i / sin r

Question 34

standing wave

Answer 34

a wave formed when a wave is reflected and the reflected wave interferes with the forward moving wave

Question 35

superposition

Answer 35

a resultant wave formed by the addition of the displacements of individual waves when they interfere

Question 36

total internal reflection

Answer 36

occurs when a wave is travelling into a less dense medium and when the angle of incidence at the boundary is greater than the critical angle

Question 37

transverse wave

Answer 37

the particles of the medium oscillate perpendicular to the direction of energy transfer

Question 38

wave

Answer 38

a movement of energy through a medium

Question 39

wave speed (c)

Answer 39

distance travelled per unit time by the energy of the wave

Question 40

wavefront

Answer 40

line connecting points along a wave that are in phase