7 CLASS FA 4 PROJECT WORK
Name
of the Project:
Preparation of Newton’s Disc and
Demonstration of Formation of White Light
Aim:
To prepare Newton’s disc and
demonstrate that white light is a combination of seven colours.
Objectives:
To understand that white light
consists of seven colours.
To construct Newton’s disc using
simple materials.
To observe the effect of mixing
colours by rotation.
Tools:
Circular cardboard disc, Poster
colours (VIBGYOR), Brush, Pencil and ruler, Pin / refill of a ball pen, Eraser
Procedure:
A circular cardboard disc was
taken and divided into seven equal sectors.
Each sector was painted with one
of the seven rainbow colours in the order: Violet, Indigo, Blue, Green, Yellow,
Orange, and Red.
A small hole was made at the
centre of the disc.
The disc was fixed loosely on the
tip of a ball pen refill so that it could rotate freely.
The disc was rotated slowly and
then rapidly in daylight.
The appearance of the disc was
carefully observed in both cases.
Analysis:
|
Condition of
Disc
|
Observation
|
Reason
|
|
Disc not
rotating
|
Seven separate
colours were clearly visible
|
Colours were
not mixed
|
|
Disc rotating
slowly
|
Colours
partially mixed
|
Partial mixing
of colours
|
|
Disc rotating
rapidly
|
Disc appeared
whitish
|
Complete mixing
of seven colours
|
|
Disc stopped
rotating
|
Colours
appeared again
|
Mixing stopped
|
Conclusion:
When Newton’s disc was rotated
rapidly, all the seven colours mixed together and appeared white. This proved
that white light is a mixture of seven colours.
Resources:
Secondary School Science Textbook
Classroom notes and teacher
guidance
Art and craft materials available
at school
