Waves

Question 1

What is a wave?

Answer 1

A vibration that transfers energy

Question 2

What are the two types of waves?

Answer 2

Longitudinal and transverse

Question 3

Define frequency

Answer 3

Number of complete wave cycles per second

Question 4

Define period

Answer 4

Time taken for one complete wave cycle

Question 5

What are longitudinal waves?

Answer 5

Waves where the direction of oscillation is parallel to the direction of propagation

Question 6

Give an example of a longitudinal wave

Answer 6

Sound waves, shock waves, or compressions travelling along a slinky

Question 7

What are transverse waves?

Answer 7

Waves where the direction of oscillation is perpendicular to the direction of propagation

Question 8

Give an example of a transverse wave

Answer 8

Water waves or waves on a string

Question 9

What is displacement in a wave?

Answer 9

Distance between a certain point on a wave and the equilibrium position

Question 10

Define amplitude

Answer 10

Maximum displacement of a wave from the equilibrium position

Question 11

What is a compression in a longitudinal wave?

Answer 11

A region of high density

Question 12

What is rarefaction in a longitudinal wave?

Answer 12

A region of low density

Question 13

Define polarization

Answer 13

The orientation about which a transverse wave oscillates

Question 14

What happens to intensity when unpolarized light passes through a polarizer?

Answer 14

The intensity decreases by 50%

Question 15

How do polarized sunglasses work?

Answer 15

They use vertical polarisers to block the glare from light reflected off of horizontal surfaces

Question 16

How do 3D glasses work?

Answer 16

They use two perpendicular polarizers to allow only one of two images to be seen by each eye

Question 17

What occurs when a wave encounters a boundary between two media?

Answer 17

It can reflect, refract, or get absorbed

Question 18

Define reflection

Answer 18

When a wave bounces off a surface

Question 19

Define refraction

Answer 19

Change in direction and wave speed when a wave passes from one medium into another

Question 20

What is diffraction?

Answer 20

Waves spread out as they go around an obstacle

Question 21

Define intensity in terms of waves

Answer 21

Power per unit area, measured in Watts per metre squared

Question 22

What is the principle of superposition (interference)?

Answer 22

When two or more waves overlap, the resulting displacement is the sum of the displacements of each of the overlapping waves

Question 23

What does it mean for waves to be in phase?

Answer 23

They are at the same point along their wave cycle at the same time

Question 24

What is constructive interference?

Answer 24

When two or more waves are in phase, resulting in a greater displacement

Question 25

What is destructive interference?

Answer 25

When two or more waves are out of phase, resulting in cancellation

Question 26

Define stationary wave

Answer 26

Occurs when two waves overlap, travelling in opposite directions, producing a pattern of nodes and antinodes

Question 27

What are nodes in a standing wave?

Answer 27

Regions where destructive interference causes the waves to cancel out

Question 28

What are anti-nodes in a standing wave?

Answer 28

Regions where the two waves are in phase and correspond to maximum displacement

Question 29

What are harmonics, in the context of standing waves?

Answer 29

Different modes of oscillation of standing waves

Question 30

What type of wave is produced in a guitar string?

Answer 30

Transverse wave

Question 31

What is the key difference between stationary waves and progressive waves?

Answer 31

No net transfer of energy occurs in stationary waves

Question 32

What is linear mass density?

Answer 32

The mass per unit length

Question 33

What is the rule for standing waves in pipes?

Answer 33

An open end is always an anti-node, and a closed end is always a node