3.1 - Waves

Question 0

What is a test for waves?

Answer 0

Interference, as waves pass through each other during interference, whereas particles would simply reflect.

Question 1

How does the frequency of a wave depend on its source?

Answer 1

The frequency of a wave is the same as the frequency of the source producing it

Question 2

What does the energy of a wave depend on?

Answer 2

The waves amplitude

Question 3

What does ‘In Phase’, ‘Exactly Out of Phase’ and ‘Coherent’ mean?

Answer 3

• In Phase means that two points on a wave are vibrating in exactly the same way at the same time
• Exactly Out of Phase means that two points are vibrating in exactly the opposite way at the same time
• Coherent means that two sources are oscillating with the same frequency and have a constant phase relationship

Question 4

What is ‘Constructive Interference’?

Answer 4

Interference is when two waves meet and pass through each other. Constructive interference occurs when the waves meet in phase, and the energies of the waves are added together.

Question 5

What is ‘Destructive Interference’?

Answer 5

Interference is when two waves meet and pass through each other. Destructive interference occurs when the waves meet out of phase, and the energies of the waves are subtracted.

Question 6

Name 4 behaviours of waves

Answer 6

• Interference
• Diffraction
• Reflection
• Refraction

Question 7

What are 3 conditions that affect the spacing of interference regions of two sources?

Answer 7

• Increasing the separation of two sources will increase the number of interference regions and decreases the spacing of the regions
• Increasing the wavelength/decreasing the frequency of two sources will decrease the number of interference regions and increases the spacing of the regions
• Increasing the distance at which the interference pattern is observed will increase the spacing of the regions

Question 8

What is the effect of a diffraction grating on a monochromatic light beam?

Answer 8

A series of spectra are produced by interference

Question 9

What are the approximate values for the wavelengths for red, green and blue light?

Answer 9

• Red = 644nm
• Green = 509nm
• Blue = 480nm

Question 10

How does the white line spectra produced by a GRATING compare with that produced by a PRISM?

Answer 10

Red is deviated most by grating, whereas red is deviated lease by prism