PARTICLES AND WAVES - Diffraction, Snell's Law and total internal reflection

Question 1

What should the path difference be between waves to produce maxima and minima

Answer 1

For a maxima, the path difference is a whole no. of wavelegnths; for a minima, the path difference is an odd no. of half wavelengths

Question 2

Identify the variables which determine the spacing between the maxima and the minima

Answer 2

The distance ,d, between adjacent slits; the wavlength; the distance, D, between the slits

Question 3

Define the term ‘absolute refractive index

Question 3

State what is meant by the term refraction

Answer 3

the change in direction when a wave moves fro one medium to another

Question 4

Give the 3 ways that the refractive index of a material can be determined

Answer 4

Tha absolute refractive index is the refractiove index of a material compared to the refractive index of a vacuum

Question 5

Define the term critical angle

Answer 5

the critical angle is the angle of incidence for a material that results in an angle of refraction of 90 degrees

Question 6

What happens when the angle of incidence of a material is greater than the critical angle

Answer 6

the light is totally internally reflected