Required prac 9 P2

Question 1

why may it be inaccurate

Answer 1

the width of the light ray may make it difficult to locate where the centre is

Question 2

Outline the basic steps of the practical

Answer 2

Draw a straight line and a line normal to it using a protractor in the centre of the paper
Turn the light off
Place the block along the main line and shine the ray light at the position where the normal meets the box
Mark with crosses the incoming, and outgoing rays of light
Turn light on
Draw the lines in of the rays of light and then measure the angles of incidence, reflection and refraction

Question 3

What precautions should be taken with ray box

Answer 3

Dont touch any metal parts since box gets hot when in use

Switch off when not in use to prevent overheating

Question 4

What conditions are needed for this experiment and why

Answer 4

Low lighting so the rays are visible

Question 5

Which angle is the angle of incidence

Answer 5

The angle as measured between the incident (incoming) ray and the normal

Question 6

Which angle is the angle of reflection

Answer 6

The angle measured between the reflected ray and the normal

Question 7

What is the normal

Answer 7

Any line perpendicular to the surface of the mirror ?

Question 8

How do you draw the refracted ray

Answer 8

Connect the point where the ray entered the block and the point where the ray left the block on the other side with a straight line

Question 9

What does theory suggest about the angle of refraction for different materials

Answer 9

It should be different for each material depending on its refractive index

Question 10

What does theory suggest about the angle of incidence and the angle of reflection

Answer 10

Angle of incidence should be the same as the angle of reflection

Question 11

Method

Answer 11

Take a piece of A3 paper and draw a line down the centre using a ruler
Use a protractor to draw the normal
Place a glass block against the line so the normal is near the centre of the block and draw around the glass block
Turn off the lights
Use the ray box to direct a ray of light to hit the box at the normal, this is the incident ray
Now change the angle of the ray box to change the angle of incidence
At a certain angle you can see the reflected ray, and a transmitted ray
Mark the path of the incidence ray, reflected ray and transmitted ray with crosses
Turn on the lights and turn off raybox
Draw in all the rays using a ruler and connect the transmitted ray to the edge of the block then a line through the block that connects to the normal
Protractor to measure angles
Repeat with different material blocks