Colour code for carbon resistor –
In this topic we will discuss about Colour code for carbon resistor .In which we will know that how can we find the value of carbon resistor .
Before to know about this topic Colour code for carbon resistor students must have to learn about resistance and resistivity .
Colour code of carbon resistor –
A carbon resistor are made by modulating carbon into a cylinder with wire leads at the two ends . such carbon resistor is encased in plastic jackets .
The colour code for the carbon resistor is given in the table :-
To remember the value of colour coding we must keep in my mind the following sentences :-
B B ROY of Great Britain has Very Good Wife wearing Gold Silver Necklace
[ here bold capital figure gives the first name of the colour shown in the table]
Way to find the resistance of carbon resister –
(i) Colour of the first strip A from the ends indicates the first significant figure,
(ii) colours of the second strip B indicates the second significant figure of resistance,
(iii) The colour of the third strip C indicates the multiplier,
(iv) The colour of the fourth strip R indicates the tolerance limit of the resistance.
[ note- if fourth strip is not given then tolerance will be 20%]
Example- for the given carbon resistor, first strip be red, second strip be yellow, third be orange and fourth is gold. what is the resistance?
Solution- sequence of the colour band is – red, yellow, orange and gold
Therefore, value of resistance of the given resistor =24 x 103 +- 5% Ohm;