physics- the wave nature of light

chapter 18

what is monochromatic light

monochromatic light is light of only one wavelength

what is the functiion of a collimater

A collimator narrows a beam of particles or waves by either making the directions of motion more parallel or by reducing the beam's spatial cross-section

what adjustments should be made to a spectrometer 

• adjust the eyepiece until the crossthreads are in focus

• djust the telescope until the distant object is in focus

• move the slit relative to the collimater until the slit is in focus

• level the turntables by means of the levelling screws

describes youngs slit experiment

monochromatic light from onto a narrow slit . it undergoes diffraction nd illuminates two more slits where diffraction happens again and light from each overlaps eachother , interference occurs.

since the linees are line sources the interference pattern consists of a series of parallel bright and dark lines known as interference fringes

what is a grating constant 

the distance d between two adjacent slits on the grating( the width of one line and one slit)

what proof is there that light is a wave

the fact it can be polorised shows that light is a transverse wave

what is dispersion

the splitting up of white light into its consistuent colours(different wavelengths)

what is a spectrum

when light undergoes dispersion the range of colours produced is called a spectrum

describe with a diagram dispersion in a prism

what is the differnce between dispersion by a prism and in diffraction grating

• when white light is dispersed by a prism violet light is deviated the most and red the least . the opposite is true with a diffraction grating

• a prism produces one spectrum whereas a diffraction grating produces a number of spectra

name the three pairs of complementary colours

blue and yellow 

green and magenta 

red and cyan

what are complementary colours

a primary and secondary colour that when mixed gives white are called complementry colours

name two features of ultra violet light

they flouresce and give sunburn

name the different types of waves in order of increasing frequency

1. radio wave 

2. micro wave

3. infrared

4. visible light

5. ultraviolet light

6. x ray

7. gamma ray

what are properties of infrared

it causes substances on which it falls to heat up. infrared radiation can be detected by its heating effect