Resistor is a component that limits the flow of current. It is similar to the blockage in a pipe carrying water. It limits the flow of water. In many electronics applications we need to limit the current and this is acheived by putting resistor in current's path.
![resistor_pipe_rep2](/images/resistor_pipe_rep2.jpg)
The above figure shows three cases of a pipe carrying water.
Case I : In case one, water is flowing smoothly through the pipe since there is no blockage. In electronics this condition is same as a wire carrying current, where current is flowing smoothly since there is no electrical blockage in the path.
Case II : In case 2, a small blockage is introduced in the pipe and due to this blockage the water flow is reduced. This situation is similar where current flow is reduced by putting a small resistor in the path.
Case III : Case 3 shows that the blockage is further increased, which is allowing very less water to flow now. This is like putting a big resistor which allows very small current to flow through wire.
From the above analysis we can conclude following points :-
- Resistor reduces the flow of current by providing blockage.
- More Blockage will result into less flow of current.
- These blockages in electronics domain are measured in ohms, more ohms means more blockage. Hence all resistor values in electronics are measured in ohms.
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Symbolically ohms is represented by