Resistance is the property of an electrical element which defines the measure of obstacle or how much the element will resist the flow of current. Most of the electrical elements in a circuit has some resistance.
There are elements in a circuit which are specially made to increase the resistance of a circuit which are called resistors. Resistors resist the current to flow. Resistors are very important in circuit construction as they resist the flow of current, so they are used to allow specific amount of current at specific element as designed by the engineer.
In industry resistors are made by adding impurities in carbon. Clay to a carbon paste, or by winding a thin wire into a coil can be used as impurities.
The unit of resistance is Ohm (O). The upper class Greek letter omega (O) is used to denote ohms. One ohm is defined as "if 1 A current is passed through a circuit having a potential difference of 1 V then the circuit has a resistance of 1 ohm".
When there is no resistance along a path of a circuit we call it as 'short'. Short circuit can be dangerous as high current will pass through the short circuit. And if there is a high voltage source connected then short circuit can cause fire and severe damage.
The opposite of short circuit is 'open' circuit where the path of the current is broken at any point of the circuit or network. So at an open circuit current can not flow. But the voltage will appear as it is at the two open terminal of the open circuit.
There are elements in a circuit which are specially made to increase the resistance of a circuit which are called resistors. Resistors resist the current to flow. Resistors are very important in circuit construction as they resist the flow of current, so they are used to allow specific amount of current at specific element as designed by the engineer.
In industry resistors are made by adding impurities in carbon. Clay to a carbon paste, or by winding a thin wire into a coil can be used as impurities.
The unit of resistance is Ohm (O). The upper class Greek letter omega (O) is used to denote ohms. One ohm is defined as "if 1 A current is passed through a circuit having a potential difference of 1 V then the circuit has a resistance of 1 ohm".
The opposite of short circuit is 'open' circuit where the path of the current is broken at any point of the circuit or network. So at an open circuit current can not flow. But the voltage will appear as it is at the two open terminal of the open circuit.
Mr. Muhammad Saqib, M.Sc. (PAK), Research Fellow (PAK), a member of IEEE, is a Fulbright Alumnus and earned his Master’s Degree in Electrical and Power Engineering from University Of Engineering And Technology Taxila, PAKISTAN.
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