Unit 5 Waves Flashcards
Optics & sounds
True or false progressive waves carry enegery from one place to another
False ems waves dont carry energy they oscillate particles
What is phase difference
The amount of lag between waves
What is the difference between longitudinal and transverse waves
Longitudinal-vibrations move in the same direction as energy
Transverse-vibrations move perpendicular to the energy
What type of wave can be polarised
Only transverse waves can be polarised
State the principle of super position
When 2 or more waves cross, the resultant displacement equals the vector sum of the individual displacement
What are stationary waves
A superposition of 2 waves in opposite directions with same frequency and
Length
What is a node
A point where no displacement will occur
What is an antinode
a point where there is maximum displacement of amplitudr
What is whitelight
It is a mixture of all light colors
Why can blue and red be seen when light is diffracted
When whitelight is shone through a slit it eill diffract and due to the different color of each light it will produce a spectra of colors
Why do dark fringes occur in double slit
This is because destructive interference is taking place
How does youngs experiment give evidence for wave nature of light
The expriement proves thay light could diffract and intefere which are wave properties
Give 2 applications of diffraction grating
The production of spectra help identify elements and help with x-ray
Explain the appearence of the zero order line in the pattern when whitelight passes tehough diffraction grating
The zero order line is white because all the wavelengths of the light just pass straight through the grating
What is a diffraction grating
A diffraction grating consists of a plate with many closed spaced parallel slits ruled on it
What are the types of spectra
Continuous, line emission,line absorption
What is a line emission spectra
When a glowing gas lamp de excites its electrons they emit light at specific wave lengths that form a vertical seperate lines
Total internal reflection is formed when
If the angle of incidence is increased to a cerain value known as the critcal angle
What is the equation for a refractive index
The speed of light in a vacuum / speed of light in the substance
Whqt is monochromatic light
Light waves with one wavelength
What is the zero order
The line of maximum brightness at the middle
How to find the angle between
The incident and beam and maxima
d sin0 =ny
how is the interference pattern produced
once light reaches each slit the waves diffract and interfere with each other
The effects of a larger wavelength
The wavelength is correlated to the angle so there will be more spread
Application of a spectrometer
Helps to identify elements
