2.2 Refraction

Question 1

Refraction

Answer 1

Change in direction of light as it moves between 2 different mediums causing a change in speed

Question 2

Snell’s Law

Answer 2

For light travelling from one medium to another the ratio of sin i/sin r is a constant

Question 3

What happens to wave as it passes from one medium to another where it travels at slower speed?

Answer 3

Wave bends towards normal
Speed of wave decreases
Frequency remains constant
Wavelength decreases

Question 4

Refractive index

Answer 4

Ratio of the sin of angles in medium one to the sin of the angle in material two

Question 5

Refractive index formula

Answer 5

Speed of light in a vacuum/air / speed of light in material

Question 6

Refractive index in air/vacuum

Answer 6

1

Question 7

Relative refractive index

Answer 7

Light moving from one medium to another where neither is air/vacuum

Question 8

Relative refractive index formula

Answer 8

1n2 = c1/c2 = n2/n1 = sin01/sin02

Question 9

How is snell’s law verified from graph?

Answer 9

Gradient of graph is a constant
Sin i directly proportional to sin r - straight line through the origin

Question 10

What happens if the direction of light is reversed?

Answer 10

Material 2 to material 1
Refractive index 2n1 is related to 1n2 like this:
2n1 = 1/1n2

Question 11

Total internal reflection

Answer 11

Ray of light passing from glass into air bending away from normal

Question 12

Critical angle

Answer 12

Particular value of angle of incidence where the angle of refraction is 90

Question 13

Conditions for total internal reflection

Answer 13

Angle of incidence = greater than critical angle
Light must be travelling from a more dense material towards the less dense material (higher rf to a lower rf)

Question 14

Equation for the critical angle

Answer 14

N = 1/sin0c