Module 2 - Waves

Question 0

Amplitude

Answer 0

The maximum displacement of a wave from its resting position, measured in metres.

Question 1

Absorption spectrum

Answer 1

A spectrum of dark lines across the pattern of spectral colours produced when light passes through a gas and the gas absorbs certain frequencies depending on the elements in the gas.

Question 2

Antinode

Answer 2

A point of maximum amplitude along a stationary wave. (m)

Question 3

Coherence

Answer 3

Two waves with a Constant phase relationship.

Question 4

Diffractio

Answer 4

When a wave spreads out after passing around an obstacle or through a gap.

Question 5

Emission spectrum

Answer 5

A pattern of colours in light, each colour having a specific wavelength.

Question 6

Frequency

Answer 6

The number of oscillations per unit time, measured in hertz

Question 7

Fundamental frequency

Answer 7

The lowest frequency in a harmonic series where a stationary wave forms.

Question 8

Harmonics

Answer 8

Whole number multiples of the fundamental frequency of a stationary wave.

Question 9

Intensity

Answer 9

The energy incident per unit square metre of a surface per second, measured in warts per metre squared.

Question 10

Line spectrum

Answer 10

Spectrum produced by a material that contains only certain frequencies due to electron transitions between energy levels.

Question 11

Longitudinal wave

Answer 11

A wave where the oscillations are parallel to the direction of the wave propagation, e.g. Sound

Question 12

Malus’ law

Answer 12

A physical law describing the change in intensity of the transfers waves passing through a Polaroid analyser.

Question 13

Monochromatic light

Answer 13

Light waves with a single frequency (or wavelength).

Question 14

Period (T)

Answer 14

The time taken for one complete a pattern of oscillation, measured in seconds.

Question 15

Phase difference

Answer 15

The difference by which one wave leads or lags behind another. For example in phase waves are in step with each other. In ways that are completely out phase 1 wave is half a wavelength in front of the other. Measured in radians.

Question 16

Plane polarised wave

Answer 16

A transverse wave oscillating in only one plane.

Question 17

Polarisation

Answer 17

The process of turning an unpolarised wave into a plane polarised wave (for example, light passing through a polarised filter).

Question 18

Progressive wave

Answer 18

A wave that travels from one place to another

Question 19

Radian

Answer 19

An angle or phase difference.

One radian is equal to the angle subtended at the centre of a circle by an arc of circumference.

Question 20

Spectral line

Answer 20

Aligned relating to specific frequency either missing from absorption spectrum or present in an emission spectrum.

Question 21

Spectrum

Answer 21

A collection of waves with a range of frequencies for example, spectrum and electromagnetic spectrum.

Question 22

Standing/stationary wave

Answer 22

A wave formed by the interference of two waves travelling in opposite directions.

Question 23

Superposition

Answer 23

The principal states that when waves of the same type exist at the same place the resultant wave will be found by adding the displacement of each individual wave.

Question 24

Threshold frequency

Answer 24

The lowest frequency of electromagnetic radiation that will result in the omission of photoelectrons from a specified metal surface.

Question 25

Transverse wave

Answer 25

A wave with the oscillations are perpendicular to the direction of wave propagation e.g. water waves electromagnetic waves etc.

Question 26

Wave

Answer 26

A series of vibrations the transfer energy from one place to another.

Question 27

Young’s double slit

Answer 27

And experiments to demonstrate the wave nature of light by superposition and interference.

Question 28

Fuse

Answer 28

Electrical component designed to heat up, melt and break the circuit (hence stop the current) when a specified amount of electric current passes through it. Used as a safety device.