Practical 14 - Measurement of the refractive index of a material

Question 1

Which equation will we use to calculate the refractive index of the material and what is this?

Answer 1

n1sinθ1 = n2sinθ2
Snell’s law

Question 2

What will be the values inputted into n1sinθ1 = n2sinθ2 for this practical?

Answer 2

θ1 = angle of incidence
θ2 = angle of refraction
n1 = 1 (assume that the incident ray is travelling through air)
n2 = refractive index

Question 3

What type of graph would we plot and what information would this give us?

Answer 3

sin θ1 (y-axis)
sin θ2 (x-axis)
Straight line
Gradient = refractive index, n

Question 4

Draw and label the set up of this practical

Answer 4

(See notes)

Question 5

How can we measure the angles of refraction and incidence?

Answer 5

By drawing in the line joining the incident and emergent rays for different values of the angle of incidence and measure using a protractor after drawing in the normals

Question 6

Where do we measure our angles of incidence and refraction from?

Answer 6

The normals (drawn in)

Question 7

How many angles of incidence do we need to use?

Answer 7

At least 5