Resistance: a current limiting element. When the resistance is connected to the circuit, the resistance value of the resistor is fixed, usually two pins, which limit the current through the branch it is connected to. Those whose resistance cannot be changed are called fixed resistors. Variable resistance is called a potentiometer or variable resistor. The ideal resistor is linear, that is, the instantaneous current flowing through the resistor is proportional to the applied instantaneous voltage. A variable resistor for voltage divider. One or two removable metal contacts are pressed tightly against the exposed resistance body. Contact position Determines the resistance between any end of the resistance body and the contact.

500kw load bank
 

Low-power resistors are usually made of carbon film enclosed in a plastic case, while high-power resistors are usually wire-wound resistors, which are made by wrapping a high-resistivity metal wire around a porcelain heart.

 

If the value of a resistor is close to zero ohms (for example, a large cross section wire between two points), the resistor does not obstruct the current, and the circuit that connects the resistor is short-circuited, and the current is infinite. If a resistor has infinite or large resistance, the circuit connected to the resistor is considered open and the current is zero. The resistors commonly used in industry fall between the two extremes. They have a resistance that can pass through a current, but not as much as in a short circuit. A resistor limits the flow of water in a manner similar to that of a small pipe connected between two large pipes.