# Two Resistance A and B have Colour Codes

By Varadi Hema|Updated : July 29th, 2022

Two resistors, a and b, have colour codes: orange, blue, white, brown, red, and green. Then the ratio of their resistances a:b is
A. 3:1
B. 1:3
C. 3×104 :1
D. 1:3×104
Select the correct answer from the above-given options

## Two resistors, a and b, have colour codes: orange, blue, white, brown, red, and green. Then the ratio of their resistances a:b is 3×104 :1.

Solution:

Resistor colour coding uses coloured bands printed on the resistor body to calculate the resistance value.

Generally, there will be 3, 4 and 5 colour band resistors; each colour band position and colour will have a particular specification significant value.

The first two colour bands indicate significant value; the third band will indicate multiplier value.

The fourth band indicates the tolerance if present, and if not, the tolerance of that resistor will be 20%.

If present, the fifth band indicates the resistor's temperature coefficient. And Colour coding and its values are shown below table.

 Colour Digit Multiplier Tolerance Black 0 1 Brown 1 101 1% Red 2 102 2% Orange 3 103 Yellow 4 104 Green 5 105 0.5% Blue 6 106 0.25% Violet 7 107 0.1% Grey 8 108 0.05% White 9 109 Gold 5% Silver 10% None 20%

So, from the above information, we can calculate the resistance value of resistors a and b.

Resistance of a:

Given colour coding for resistor a: orange, blue, white

So, the resistance of a =36×109 Ω

Resistance of b:

Given colour coding for resistor b: brown, red, green

So, the resistance of b =12×105 Ω

## The ratio of resistances a and b =36×109:12×105 =3×104:1

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