Waves and Optics

Question 1

What is a transverse wave?

Answer 1

A type of wave that is perpendicular to the direction of the energy transfer

Question 2

What is a longitudinal wave?

Answer 2

A type of wave that is parallel to the direction of the energy transfer

Question 3

Amplitude

Answer 3

the maximum displacement of a particle from its equilibrium position. The intensity of a wave depends on amplitude

Question 4

Frequency

Answer 4

the number of cycles or vibrations of a particle per second or the number of complete waves passing a point per second

Question 5

What is diffraction?

Answer 5

When waves spread out as they pass through a gap or around an object. If light does this, it can be said that light has wave-like properties

Question 6

What does it mean when two waves are anti-phase?

Answer 6

This means that they have a phase difference of pi radians or 180 degrees so they are 1/2 of a wave cycle apart

Question 7

What does it mean when two waves are in-phase?

Answer 7

This means that they have a phase difference of 2 pi radians or 360 degrees so they are a full cycle apart

Question 8

How is a progressive wave formed?

Answer 8

A wave that transfers energy from one point to another without transferring the medium itself

Question 9

How is a stationary wave formed?

Answer 9

A stationary wave is a wave produced by the superposition of two progressive waves moving in opposite directions. The progressive waves must have the same amplitude and wavelength.

Question 10

2 conditions for total internal reflection

Answer 10

The incident substance must have a larger refractive index than the other substance
The angle of incidence must exceed the critical angle

Question 11

What is dispersion?

Answer 11

Dispersion is the separation of white light in its separate components. This occurs because each different colour is refracted by a slightly different amount. Each wavelength has a slightly different refractive index. Red light is always refracted the least