Hypothesis
“When you increase the angle of incidence, you increase the
angle of refraction”
Equipment
Ray box and slits
Rectangular glass block
Protractor
Ruler and pencil
Plain paper
Method
Place the glass block on the paper and draw around it. Add a
normal to the diagram. Shine a narrow beam of light at the point where the
normal hits the glass block. Draw 2 crosses along the incident ray and 2
crosses along the ray that leaves the block on the other side of the block.
Take the glass block away and connect up the rays. Measure the angle of
incidence and the angle of refraction and record in a table. Adjust the angle
of incidence and repeat the process.
Variables
Independent variable: Angle of incidence (measured with a
protractor)
Dependent variable: Angle of refraction (measured with a
protractor)
Control variables: Width of beam, brightness of beam, colour
of beam, refractive index of glass block
Risk Assessment
This is a very low risk experiment. Care must be taken to
avoid burns from the ray box if it gets hot. To avoid this, keep the voltage
low and turn off the ray box in between readings.