More about interference

Question 1

Why cant to lamp bulbs not form an interference pattern?

Answer 1

they emit light waves randomly

Question 2

What colour light produces the largest fringe seperation?

Answer 2

red, largest wavelength

Question 3

What does it mean by a laser is a coherent light source?

Answer 3

doesnt need to pass through a slit

the photons in a laser beam are in phase

Question 4

Describe the fringes formed from white light

Answer 4

central fringe, in same position, and white because every colour contributes at the centre patter

each component produces its own fringe pattern

inner fringes are tinged with blue on the inner side and red on the outer side, this is because red fringes are more spaced out than the blue fringes and the two fringe patterns do not overlap exactly

the outer fringes merge into an indistinct background of white light, becoming fainter with increasing disctance from the centre

this is because when fringes merge, different colours reinforce and therefore overlap