Chapter 11 - Waves 1 Flashcards
(25 cards)
Define displacement on a wave.
Distance from the equilibrium position.
Define amplitude.
Maximum displacement from equilibrium position.
Define wavelength.
Minimum distance between 2 points in phase on adjacent waves.
Define period of oscillation.
Time taken for a wave to move one wavelength past a given point.
Frequency
Number of wavelengths passing a given point per unit time.
Define wave speed.
The distance travelled by a wave per unit time.
Define phase difference in a progressive wave.
The difference between the peaks of two different waves.
What is specular reflection?
When light hits a smooth surface, and angle of incidence = angle of reflection.
Diffuse Reflection
When light hits a bumpy surface, and it scatters.
What is refraction?
When a wave changes direction when travelling from one medium to another.
What is diffraction?
When a wave travels through a gap or around an obstacle and spreads out.
Define intensity.
The amount of energy per second per square meter of surface.
Define refractive index.
A measure of how much a substance can refract a light ray.
What is Snell’s law?
n₁sinθ₁ = n₂sinθ₂
What is the wavelength of a radio wave?
10⁶ to 10⁻¹
What is the wavelength of a microwave?
10⁻¹ to 10⁻³m
What is the wavelength of infrared radiation?
10⁻³ to 7x10⁻⁷m
What is the wavelength of visible light?
7x10⁻⁷ to 4x10⁻⁷m
What is the wavelength of ultra violet radiation?
4x10⁻⁷ to 10⁻⁸
What is the wavelength of an X-ray?
10⁻⁸ to 10⁻¹³m
What is the wavelength of a gamma ray?
<10⁻¹⁰m
What is Total Internal Reflection (TIR)?
Occurs when light strikes the boundary between two media and is reflected not refracted.
What are the conditions for TIR?
-Travelling from a higher to a lower refractive index.
-Light must strike the boundary at an angle above the critical angle.
Critical Angle Formula
sinC = 1/n
