Resistor is a very vital electronic component used in most of the circuits. The value of resistor is marked on it in colour coded form. There is a special code to read this value. Resistor: Value reading

In this activity, we will design a handy tool resistance wheel which will eliminate the need to memorize the values of color rings.

Material Used: Card Board, geometry box, color pencils.

  • Draw four circles on a card board of radius 5 cm, 4 cm, 2 cm and 1 cm. Mark there center. Cut these circles. Divide each circle in to 11 parts (10 parts of angle 33 degree, 1 part of 30 degree).

  • Color ten parts of the circle in the following sequence: Black, Brown, Red, Orange, Yellow Green, Blue Violet, Grey and White.

  • Label each circle as per the table given below.
  • The first and second ring is the value ring. The third ring is multiplier and the fourth ring is the tolerance one which is usually gold or silver.
Color I Ring II Ring III Ring
Black 0 0
Brown 1 1 0 Ω
Red 2 2 00 Ω
Orange 3 3 KΩ
Yellow 4 4 0KΩ
Green 5 5 00KΩ
Blue 6 6 MΩ
Violet 7 7 0MΩ
Grey 8 8 00MΩ
White 9 9 GΩ
  • Align all four circles at the centre. Make a hole at the centre of each circle.  Take a splitter nail. Insert the nail through all the circles. Bend the nail at the back.

  • Our resistance wheel is ready.