Chapter 3 - Waves

Question 1

What is a Progressive Wave?

Answer 1

A Progressive Wave is a wave that carries energy from one place to another.

Question 2

Define Displacement

Answer 2

Displacement is how far a point on the wave has moved from its undisturbed pattern.

Question 3

Define Amplitude

Answer 3

The Amplitude of a wave is the maximum magnitude of Displacement from the Equilibrium Point.

Question 4

Define Wavelength

Answer 4

The Wavelength is the length of one whole wave Oscillation.

Question 5

Define Period

Answer 5

The Period is the time taken for one whole wave cycle.

Question 6

Define Frequency

Answer 6

The Frequency of a wave is the number of whole wave Oscillation per second passing a given point.

Question 7

Define Phase

Answer 7

The Phase is the measurement of the position of a certain point along the Wave Cycle.

Question 8

Define Phase Difference

Answer 8

The Phase Difference is the amount by which one wave “lags” behind another wave.

Question 9

Frequency and Period are linked, What is the equation that links Frequency and Period?

Answer 9

Frequency = 1/ Time Period

Question 10

What are the two equations for Wave Speed?

Answer 10

c (Wave Speed) = d (Distance) / t (Time)

c (Wave Speed) = f (Frequency) X λ (Wavelength)

Question 11

What is the speed of Electromagnetic (EM) Waves in a Vacuum?

Answer 11

C is often used as the speed of light in a vacuum. All EM Waves, including light, travel at a speed of 3.00X10^8m/s

Question 12

Name all the types of Electromagnetic Waves

Answer 12

All EM Waves
(biggest wavelength to smallest) :

Radiowave
Microwave
Infrared Radiation
Visible Light
Ultraviolet
X-Rays
Gamma Rays

Question 13

What is a Transverse and Longitudinal Wave?

Answer 13

A Transverse Wave is a wave that oscillates at a right angle to the direction of energy propagation.

A Longitudinal Wave is a wave that oscillates parallel to energy propagation.

Question 14

Name a Transverse Wave

Answer 14

Any Electromagnetic Wave:
Radiowave, microwave, infrared radiation, visible light, ultraviolet, x-ray and gamma rays.
S-Waves

Question 15

Name a Longitudinal Wave

Answer 15

Sound Waves
P Waves

Question 16

What is a Polarised Wave?

Answer 16

A Polarised Wave is a Wave that Oscillates in one direction only.

Question 17

What happens if you shine a light through two Polarising Filters are at right angles to eachother?

Answer 17

As the wave gets polarised in one direction, the light cannot pass through the second polarising filter, meaning no light appears at the other end.

Question 18

True or false, Polarisation can only happen for Transverse Waves

Answer 18

True, Polarisation can only occur in Transverse waves as Transverse waves Oscillate at right angles

Question 19

True or false, Polarisation can only happen for Longitudinal Waves

Answer 19

False, Polarisation can only occur in Transverse waves as Transverse waves Oscillate at right angles

Question 20

How are polarising filters used in antennas

Answer 20

TV and radio signals are usually plane polarised by the orientation of the rods on the transmitting aerial, so the receiving aerial must be aligned in the same plane of polarisation to receive the signal at full strength.

Question 21

What is a Stationary Wave?

Answer 21

A Stationary Wave is a wave which transfers NO energy and whose positions of maximum and minimum amplitude are constant.

Question 22

What is a Node?

Answer 22

A point on a Stationary Wave where the displacement is 0

Question 23

What is an Antinode

Answer 23

An Antinode is the point on a stationary wave where there is maximum displacement from the equilibrium point

Question 24

What are the conditions for a Stationary Wave to be produced?

Answer 24

• The waves must be Coherent (Same Frequency, Wavelength and Phase Difference) and have the same Amplitude
•They must be travelling in opposite directions

Question 25

How are Stationary Waves produced?

Answer 25

A Stationary Wave is formed from the Superposition of 2 Progressive Waves, travelling in opposite directions in the same plane, with the same Frequency, Wavelength and Amplitude.

Question 26

Describe the First Harmonic for a Stationary Wave with two closed ends

Answer 26

It consists if 2 Nodes at either end and an Antinode in the middle. Image

Question 27

Describe the Second Harmonic for a Stationary Wave with one open and one closed end.

Answer 27

The Second Harmonic consists of two Nodes and two Antinodes, with one of the Nodes at the closed end and one of the Antinodes at the open end.