Now the electrical resistance, electronic, mechanical, aerospace and other fields are widely used, but its role is nothing more than the following:

A, partial pressure

When a resistor and other components such as lighting in the circuit in series, flowing through the resistor and the lighting of the same current, and resistance and lighting and respective voltage equal to resistance and lighting as a whole from both ends of the total voltage. At this time, the resistance plays a role of partial pressure.

Two, shunt

While flowing through the resistor current flowing through the lamp current and equal to the total current flowing through the resistor and the lighting of the resistor voltage and the terminal voltage of the bulb are same as a resistance and the other components such as lighting in the circuit in parallel. At this time, the resistor serves as a shunt.

Three, impedance matching

Impedance matching refers to is in the process of signal transmission, in order to get the maximum power output of a kind of state, while the use of some method makes the load impedance and excitation source internal impedance of mutual adaptation process. And one of the methods is by changing impedance force. In this case, resistance to is the impedance matching function.

Four, filter

The resistor and the capacitor in series RC charge and discharge circuit, first switch s connection point B, as shown in the figure below, no charge on the capacitor C, at both ends of the voltage is zero, after the switch S is placed on a point, then the power through the resistor R began to charge the capacitor, when both ends of the capacitor charge increases to balance circuit, power no longer to capacitor charging, after the switch S is placed in B, capacitor began to discharge, at both ends of the charge gradually reduced, reduced to zero no longer discharge, then the switch S is placed in a begin charging… Inthe charge and discharge in an infinite loop, we will play a role in R resistance is calledfiltering effect.