Laser and color filter
The materials required for the experiment:
- A 1 watt red laser pointer
- A 1 watt green laser pointer
- A 1 watt blue laser pointer
- A holder for the laser pointer
- A red glass filter
- A green glass filter
- A blue glass filter
- A watt-meter
- A solar cell
- A 1-meter ruler
1. For this experiment, the independent variable is the color of the glass filter (red, green and blue) and the color of the laser pointer – red, green and blue. The dependent variable is the amount of power of the laser beam. This is determined by using a solar cell to measure the power of the light. The constants (control variables) are the distance of the colored glass filter and the solar cell from the laser pointer.
2. The red laser pointer is mounted on the holder. The solar cell is connected to the watt meter and placed 1 meter away from the laser pointer. The laser pointer is turned on and aligned to point to the center of the solar cell. The power reading of the solar cell is recorded in the table given below.
3. Procedure 2 is repeated with the green and blue laser pointers. The wattage measurements are recorded in the table given below.
4. Procedures 2 and 3 are repeated, this time with the inclusion of the glass filters. The red, green and blue colored glass filters are each placed at a distance of 500mm between the laser pointer and the solar cell. The wattage readings are measured and recorded in the table given below.
The colored glass will filter and block the beam of the laser pointer.