BACKGROUND

Coloured lights and their nature are stipulated in the Integrated Science Curriculum for Secondary School. Nevertheless, the concepts on addition of primary coloured lights, subtractive mixing of secondary colours, and subtractive mixing on coloured objects are not taught via experiments. This is due to the inconvenience of setting up two or three sources of light and the unavailability of appropriate apparatus in the market. Furthermore, the conventional ray box does not produce strong coloured light. Given these problematic situations, an innovative apparatus was improvised to allow experimentation while studying the nature of light.

OBJECTIVES

1. To arouse the interest of students in science through experiments.
2. To relate science to everyday life
3. To integrate science with other fields of study.
4. To help science teachers teach these topics more effectively.

BENEFITS FOR TEACHING-LEARNING PROCESS

1. This device is simple and pedagogically effective.

2. It provides a conducive environment for students to learn this topic. With the help of the device, students can be actively involved in "hands-on" and "minds-on" activities.

3. The results of mixing different coloured lights can clearly be obtained.

4. Students can draw conclusions through experimental results and theoretical construct.

5. This device also enables science teachers to bring drama into action in the science laboratory or AVA room.

6. Scientific knowlwdge is seen to be related to our every day life. Hence, it enhances the integration of science with other fields of study.

7. Students will feel that learning science is fun and this will lead to a better science appreciation.

APPARATUS/MATERIALS NEEDED

A slide projector, white screen or white wall, slides of different coloured filters (red-blue-green, turquoise-yellow-magenta, yellow-blue, turquoise-red, magenta-green, red, green, blue, turquoise, yellow, and magenta), and reflector.

CONSTRUCTION OF TEACHING AIDS

1. Self-made slides of different coloured filters.

(Please refer to Photo 7-1P)

(Please refer to Photo 7-2P)

IMPLEMENTATION

1. Usage and arrangement of the apparatus.

2. When the projector is switched on, the desired coloured lights will be reflected by the reflector on to the screen. This method will produce reflected coloured lights which are strong and clear enough for study.

3. By turning the screws at the reflector, the angles of the mirrors can be adjusted to converge the coloured lights. Therefore, the result of the mixed coloured light can easily be observed.

4. By securing a colour filter at position X, the nature of the subtractive mixing of colours can be studied.

5. By placing some coloured objects at position Y, the nature of subtractive colour on coloured objects can be studied too.

6. This experiment can be carried out in AVA room other than in the science laboratory.

7. In darkness, some students can be asked to put on coloured clothing and stand in front of the screen.

8. By switching on the projector with different coloured slides, the students will be able to see the colours change on the clothes.

9. Let the students draw conclusion on their observations.

10. With the help of this experiments, the students will appreciate more the effect of stage lights on the clothing of actors.

SUGGESTIONS FOR MODIFICATION

1. Students should be explicitly taught how to work in a cooperative manner, emphasizing the needs for positive interdependence (i.e. sharing of resources and assigning roles) and individual accountability.

2. Students should be encouraged to tabulate their observations systematically.