Question

A carbon resistor is marked in colour bands of red, black, organ and silver. What is the resistance and tolerance value of the resistor?

Answer 1

Hint: The resistance is defined as the hurdles or the obstacles which block the path of the flow of current and due to which there is voltage drop in the circuit .The resistors have given standard colour for the identification of the value of resistance.

Complete step by step answer:
The resistance is coloured so that the resistance can be found easily and there is no need to measure the resistance again and again. The two rings from left indicate two figures; in ohms the third ring represents the number of zero that must be placed after the two figures and the fourth ring indicates the tolerance value in percentage.
The red colour gives value 2, the black colour gives us value 0, the third ring is of orange colour which means there are 3 zeros and the fourth ring is of silver colour which means the tolerance is 10 percent.
Therefore the colour combination shows the resistance as $20 \times {10^3}\Omega $ and the tolerance is equal to 10 percent.
Additional information:The resistance is used in the circuit as a voltage dropper and limits the current. The colours and the resistance related to them are as follows black is equal to 0, brown is equal to 1, red is equal to 2, orange is equal to 3, yellow is equal to 4, green colour is 5, blue is equal to 6, violet colour is 7, grey is equal to 8 and white colour represents 9. The tolerance of the silver is 10 percent and the gold is equal to 5 percent.

Note:The students are advised to remember the colour and the figure which is related with the colour because it is very helpful in solving problem like these .The colour identification makes it easier for us to understand the value of resistance and it is not required to measure the value of resistance again and again.