snells law

Question 1

what does the refractive index (n) show us?

Answer 1

how optically dense a material is

Question 2

what does n give us a value of?

Answer 2

for how the speed of light in that materials relates to the speed of air

Question 3

what is the refractive index?

Answer 3

the property of a material

Question 4

material that are less dense have….

Answer 4

a lower refractive index

Question 5

materials that have a high optical density….

Answer 5

have a higher refractive index

Question 6

what is the equation for snells law?

Answer 6

n= sin(i)/ sin(r)

Question 7

what is the independent variable in the snells law practical?

Answer 7

angle of incidence

Question 8

what is the dependant variable in the snells law practical?

Answer 8

the angle of refraction

Question 9

what are the control variables in the snells law practical?

Answer 9

use of the same perspex block, width of the light beam, same frequency of the light beam

Question 10

what is the ray box used for?

Answer 10

to provide a narrow beam of light to reflect in the mirror

Question 11

what is the protractor used for?

Answer 11

to measure the light beam angles

Question 12

what is the sheet of paper used for?

Answer 12

to mark with lines for angle measurement

Question 13

what is the pencil used for?

Answer 13

to mark perpendicular line and angle lines on paper

Question 14

what is the ruler used for?

Answer 14

to draw lines on paper

Question 15

what is the perspex rectangular block used for?

Answer 15

to retract the light beam

Question 16

1st step?

Answer 16

place the glass block on a sheet of paper and draw around the block using pencil

Question 17

2nd step?

Answer 17

draw a dashed line normal to the outline of the block

Question 18

3rd step?

Answer 18

use a protractor to measures the angles of incidence to be studied and mark these lines on the paper

Question 19

4th step?

Answer 19

switch on the ray box and direct a beam of light at the side of the block at the first angle to be investigated

Question 20

5th step?

Answer 20

mark on the paper:
a point on the ray close to the ray box
the point where the ray enters the block
the point where the ray exists the block
a point on the exit light ray which is about 5cm away from the block

Question 21

6th step?

Answer 21

remove the block and join the points marked with 3 straight lines

Question 22

7th step?

Answer 22

replace the block within its outline and repeat the process for rays striking the block at the next angle

Question 23

what do you do with your results?

Answer 23

plot a graph of sin i on the y axis against sin r on the x axis

Question 24

what will the refractive index be equal to?

Answer 24

the gradient of the graph