Why is it not pure resistance when R is uncertain

A pure resistive circuit is when it is energized, and only heats up.

And there is no mechanical energy to do on the outside.

The work! For example: electric lights, soldering irons, irons, etc., they just heat up. They are both purely resistive circuits. However, the engine, electric fan.

Electromagnets, etc., they mainly do work externally, and heat generation is extremely secondary, so these are non-pure resistive circuits.

A non-purely resistive circuit is defined as an inductive load.

or a circuit with a capacitive load. or other circuits that can generate electromotive force (e.g., electrolysis devices and other circuits that generate electromotive force).

Why? Because some of the non-purely resistive loads can be stored when working, and some generate back electromotive force.

When the power supply voltage is low, the current is very large because the energy storage starts fast, and when the voltage is high, the current is very small because the energy storage will be full - this is the same as Ohm's law.

It's the opposite.

For a load that generates an electromotive force, when an external voltage is applied, this load is resisted by its own electromotive force, so that the actual current is significantly less than i=u r.

The above will be further studied in high school physics.

Non-resistance means that there are energy storage components such as capacitors and inductors, and the capacitive reactance of the capacitor and the inductance of the inductor change with the frequency of the current, so in general, its r is uncertain, and your r is different from the resistance value you said, which includes impedance capacitive impance. There is a formula for the calculation of the specific capacitive reactance and inductive reactance, and you can find it if you search it in the library.

You're in high school now, and if you study electronics in your freshman year and learn the basics of circuits, you'll know what capacitive impedance is.

Resistance at the high and high level is only one of the factors that hinder the current, and there are other factors that hinder the current in impure resistive circuits, and these factors can also be transformed into physical quantities in ohms.

For example: electric lights, soldering irons, irons, etc., they just heat up. They are both purely resistive circuits.

However, engines, electric fans, etc., work on the outside world in addition to heat generation, so these are non-pure resistive circuits. There are only resistors, power supplies, and wires in the circuit, and the electrical energy cannot be converted into a circuit in the form of energy other than thermal energy. In the energized state, all the electrical energy is converted into the internal energy of the circuit resistance, and part of the electrical energy is converted into resistance and part of the internal energy is converted into other forms of energy in the circuit without external work, such as engines, fans, etc., and a part of the electrical energy is converted into mechanical energy in the circuit, if the capacitance is zero, the circuit with zero inductance is a pure resistance circuit.

The electric furnace and incandescent lamp that are usually used are considered to be pure resistance circuits. But capacitance, inductance, and inductance are more or less always present in the circuit

Hello dear, the resistance of a non-pure resistive circuit can be less than, equal to, or greater than the resistance of a pure resistive circuit, depending on the type of components contained in the circuit and how it is connected. In the circuit, the pure Wangjian resistor circuit consists of a resistor, which is characterized by the fact that the current is proportional to the voltage and the resistance value is constant. Impure resistive circuits include inductors, capacitors, and other nonlinear components whose resistance values can change with current, frequency, and voltage.

For example, a circuit containing capacitors and resistors, called an RC circuit, can have a total resistance that is less than that of a pure resistive circuit. In this case, the impedance of the capacitor decreases as the frequency increases, resulting in a decrease in the total impedance of the entire circuit. On the other hand, an inductor in a non-pure resistive circuit can cause an increase in the total pulsation resistance of the circuit.

The impedance of the inductor increases with frequency, so in the case of high frequencies, the total impedance of the circuit increases. In summary, the resistance of a non-Kiling-toned pure resistive circuit can be less than, equal to, or greater than the resistance of a pure resistive circuit, depending on the component composition and operating conditions of the circuit.

Hello dear, in a circuit, the resistance size of a non-pure resistance circuit is usually smaller than that of a pure resistance circuit in the same case. This is because there are capacitors, inductors and other components in impure resistive circuits, which have certain capacitance and inductance, and can store charge and magnetic field energy, so that the flow finger of the electric comic flow is not only limited by resistance, but also affected by capacitance and inductance. For a non-pure resistive circuit, the total impedance is equal to the sum of the capacitive impedance, inductive impedance, and resistance, and the capacitance and inductive impedance are usually smaller than the resistor, so the total impedance is also smaller.

This means that the current in the impure resistive circuit will be greater at the same voltage, so for the same voltage and current, the resistance of the impure resistive circuit will be smaller than that of the pure resistive circuit. It should be noted that this is only a general rule, and the specific circuit characteristics will be affected by factors such as the size, frequency, and resistance of capacitance and inductive components, so it cannot be generalized.

The differences between pure resistance and non-pure resistance are:

1. The energy conversion is different: the electrical energy of the pure resistance circuit is all converted into internal energy; In addition to the internal energy, the electrical energy of impure resistive circuits can also be converted into other energy. For example, light energy, heat energy, and other energy.

2. The calculation method is different: the power calculation formula of pure resistance circuit can be p=ui=w t=i r=u r, and the electric heating can be used q=w=i rt=u rt=uit; The electrical power of non-pure resistive circuits can only be calculated using p=ui=w t, and electric heating can be used q=i r.

3. The relationship between work and heat is different: the current work w of a pure resistance circuit is equal to the heat q emitted by this part of the circuit, that is, w = q; The current work w of the impure resistive circuit is greater than the heat q emitted by this part of the circuit, that is, w q.

4. Ohm's law is applicable differently: pure resistance circuits are circuits that can be established by Ohm's law; A non-pure resistive circuit is a circuit where Ohm's law cannot be true.

5. The components of the circuit are different: there are only resistors, power supplies and wires in pure resistive circuits; Non-pure resistive circuits have other components besides resistors, power supplies, and wire elements.

(1) Pure resistive circuit.

In pure resistance circuits, the current only has a thermal effect, such as: electric heaters, electric irons, electric ovens, etc.;

2) Non-pure resistive circuits.

In impure resistive circuits, the electric current produces other effects in addition to the thermal effect, converting electrical energy into other energies (chemical energy, mechanical energy, etc.).

In a pure resistive circuit, BAI does not matter whether the resistance is series or DU

Parallel or series-parallel, only zhi is the impedance of only the resistor in the electrical DAO path, so u r=i. However, if there are other container parts mixed into the circuit, the situation is different, such as the coil, in addition to reducing the impedance of the resistance of the wire itself, there is also an inductive reactance, and the capacitor also has a capacitive reactance ......Therefore, in a non-pure resistive circuit, i u r, i = u r + ......

In a non-pure electric copy-resistive circuit, i is smaller than u r, because the bai resistance r is only a form of impedance, in addition, there are other du impedances, such as the alternating current through the coil, in addition to the zhi resistance, it will also produce an impedance that hinders the current, and in the pure resistance of direct current, it can be calculated with the formula i = u r because there are no other impedances except the resistor.

In addition to r, there are other impedances in the impure resistance, so the actual impedance is larger than r, which is i

The current in a non-pure resistive circuit is i=u (r + impedance + capacitive reactance).