# The role of the resistance, the resistivity calculation formula

made of resistance material, have certain structure form, the limiting current in the circuit through the role of two-terminal electronic components. Resistance cannot change called fixed resistor. Resistance of variable called potentiometer or variable resistor. The ideal resistor is linear, the instantaneous electric current through a resistor is proportional to the instantaneous voltage plus. Some special resistor, such as thermistor, pressure sensitive resistor and sensitive element, the voltage and current relationship is nonlinear. Resistor is used the largest number of components in electronic circuit, usually by the power and resistance to form different series, power supply designers choose road. The following is a small make up to bring us the resistance of the role, resistivity calculation formula of rechargeable batteries.

the role of resistance

a resistor in a circuit is mainly used to adjust and stable current and voltage, can be used as a shunt voltage divider, and also can make matching circuit load. In accordance with the requirements of circuit, can also be used for amplifying circuit, voltage negative feedback or positive feedback - Current transformation, input overload of the voltage or current protection device, but also of RC circuit as oscillation, filtering, by-pass, differential, integral time constant element and etc.

resistor ( Resistor) In everyday life, commonly known as resistance directly. Is a current limiting element, the resistor in a circuit, the resistance value of the resistor is fixed is commonly two pins, it can be restricted by its branch of the current size. Resistance cannot change called fixed resistor. Resistance of variable called potentiometer or variable resistor. The ideal resistor is linear, the instantaneous electric current through a resistor is proportional to the instantaneous voltage plus. Variable resistor for partial pressure. On the resistance of the bare body, tightly holding up one or two movable metal contact. Contact position to determine the resistance between both sides and contact resistance.

resistivity calculation formula of rechargeable batteries

resistivity ( 电阻率) Is used to represent various substances resistance characteristic quantities. Some materials of 1 m long, cross-sectional area is 1 square millimeters at room temperature ( At 20 ℃) Conductor resistance, called the resistivity of the material. The rechargeable battery resistivity calculation formula is: R = rho L/S ( Resistance R, S cross-sectional area, length of L, rho resistivity.

in certain cases, the temperature has the formula R = rho l/s of rho is resistivity, l the length of the material, s for the area. It can be seen that the resistance of the material size is proportional to the length of the material, and is in its area. By the definition of the type known resistivity: rho = Rs/l resistivity rho and conductor materials, not only is related to the temperature of the conductor. Little change in the temperature range, : almost all the resistivity of the metal linear change with temperature, namely rho = rho o ( 1 +,) 。 Type t is the Celsius temperature, rho o o ℃ when the resistivity, resistivity temperature coefficient a is.