practicals

Question 1

measuring wave properties in a solid

Answer 1

1. Set up the apparatus as shown, then adjust the frequency of the signal generator until a “solid” wave is produced
2. Once the “solid” wave is produced, record the frequency shown on the signal generator
3. Use a ruler to measure the wavelength, the length to measure will depend on the number of “solid” waves produced.
4. Repeat the procedure by adjusting the frequency until another “solid” wave is produced

• if more than one standing wave, tnen measure wavelength, and divide by no. of standing waves
• then x by 2

Question 2

investingating reflection/refraction

Answer 2

1. Slot the collimating slit into the ray box and turn on, producing a narrow ray of light.
2. Place the first block of material on top of a piece of paper. Trace around the block using a pencil.
3. Draw a normal to the block (a line at 90° to the surface of the block). Align the incident ray of light with the meeting point between the normal and the surface of the block.
4. Draw the reflected ray and refracted ray, as shown in the diagram below. Remove the block and draw a straight line between the point of reflection and the refracted ray on the other side of the block.
5. Using the protractor, measure:
   a. The angle of incidence - The angle between the incident ray and the normal.
   b. The angle of reflection - The angle between the reflected ray and the normal.
   c. The angle of refraction - The angle within the material between the normal
   and the refracted ray.
6. Repeat the experiment, using a new piece of paper for each different material of
   block.

Question 3

investgating infrared radiation

Answer 3

1. Set up the Leslie’s cube with matt black, shiny black, white and silver sides
2. Fill the cube with hot water,
3. keep the infrared detector at the same distance from cube throughout and measure IR remitted from each colour surface