SKEMA JAWAPAN (SPM) : Light, Colour And Sight

Light, colour and sight

1.  a.  i.  What is meant by primary colour.

           

            Primary colour are colours that cannot be obtained by adding two or more     colours

           ii.  List all the primary colour.

            Red, green, blue.

b.  i.  P and Q are two different filters.  For each pairs of filters stated below, state the  

    colours observed on the screen.

	Filter P	Filter Q	Light colour on the screen
i	Red	Green	No light in transmitted
ii	Yellow	Green	Green
iii	Yellow	Magenta	Red
iv	Cyan	magenta	Blue

  c.  State the variables in this experiment.

      Control variable:         White light

      Responding variable:  Light colour on the screen

      Manipulated variable: Filter P and filter Q

2. Name one secondary colour.

Yellow//magenta//cyan

Section B

                       

2. i.      a.  X:Green

b.  Y:Yellow

c.       Z:Red

      ii.  A girl wearing a red dress and a blue skirt is standing in the region X.  What is

     the colour appearing on the girl’s:

a.  dress:Black                                                 b.  Skirt:Black

     iii.  The girl now moves to region Y.  What colour appears on her

   a.  dress:Red                                                            b.  Skirt:Black

    iv.   Finally she moves to region Z.  What is the colour that appear pn her

a.  dress:Red                                                   b.  Skirt:Black

v.       She change her dress to one of different colour and her dress appears black in

           region X, Y, and Z.  What is the colour of her new dress.

          Blue.

Section C

1. a.  Suggest a hypothesis to investigate the above statement.

 Red light is scattered the most by the dust particles

      b.  Aim:     To investigate the scattering of light by milk particles

           

            Variables:

            Fixed   :           the angle and intensity of white light shining on the milk

            Manipulated:   the amount of milk particles in the milk solution

            Responding:    reddish appearance on the white screen

List of apparatus and materials:  projector, transparent aquarium, milk and water,

black  cardboard with a hole in the centre, white screen, a  glass rod.

            Procedure:

1.      The projector is switch on and light is shone on the aquarium containing water.

2.      The projector and the screen are adjusted until light appears on the screen.  The colour of the light that falls on the white screen is observed.

3.      Some milk is added into the water.  The water is stirred slowly with a glass rod.  The colour of the light that falls on the white screen is observed.

4.      Step 3 is repeated with more milk added to the water.

Tabulation of data:

Solution in aquarium	Appearance of light on the white screen
Water only
Some milk is added to the water
More milk is added to the water