1. Radio Station A - FM network using a radio wave of 93. 4 MHz (93
Radio Station A - FM network using a radio wave of 93.4 MHz (93.4 ×106 Hz)
Radio Station B - AM network using a radio wave of 856 kHz
Calculate the wavelength of each station
When Zac is standing behind a hill, he can only tune into one of the two stations. Identify which station he can hear and explain why.

2. Station A: Wavelength = 3.21 m Station B: Wavelength = 350 m
Zac will be able to hear station B because:
the radio waves from Station B have longer wavelength which means it can diffract over the hill better than the radio waves from station A.

3. NCEA 2006
Q: Give a physics reason why Roy and Sally could hear the sound of the waves when they were sitting behind a building at the beach, even though they could not see the waves.
A: This is because sound waves have a long wavelength. Light waves’ short wavelength means they will not be diffracted. (Merit)

4. The Properties of Waves
Reflection
Refraction
Superposition
Diffraction

5. Diffraction Bending of waves around a barrier or out through a gap
The longer the wavelength, the more the diffraction of waves
When passing through a gap, maximum diffraction occurs when the wavelength equals the size of the gap

8. The longer the wavelength, the more the diffraction

13. Gap – maximum diffraction occurs when the wavelength is equal to the size of the gap

14. Diffraction
&
Interference Pattern

16. What would happen if there are two gaps?

17. Dark
Bright

20. Question What would happen to the pattern if;
the screen is brought closer?
the two gaps are further apart from each other?
the frequency is increased?

21. If the screen is brought closer:
The fringes will be closer together and brighter
If the two gaps are further apart from each other:
The fringes will be further apart
If the frequency is increased: