Is there a theoretical or practical first, and the difference between theory and practice?

Philosophically speaking, matter exists before consciousness Practice is the **, motive force, and purpose of cognition Practice is the only criterion for testing whether the understanding is correct or not The reality you say is equivalent to the practice I say, the material The theory you say is equivalent to the consciousness I say, the cognition Since practice is cognitive** I think the relationship between the two is very clear The existing reality, and then there is the theory -- by the way, the process of knowing 1Practice to develop knowledge of things (perceptual cognition) 2Summarize and sublimate your own existing understanding (rational understanding) 3

Rational understanding is summarized into a theoretical stage to guide our practice, in which we constantly test and improve our theory. ~

Theoretical significance is a possibility summarized according to laws, experience, common sense, etc.

The practical meaning is the actual situation.

1. The difference between the two is that the former is the prediction that happened before something, and the latter is the summary that happened after something. Let's say:

A certain engineering team can build one house a day, and theoretically speaking, they can build 365 houses a year. In fact, they only build 200 houses a year, so it makes practical sense, to make a house, it also depends on the sky, and it can't be built on a rainy day.

2. In theory, what is read in books is actually summarized in practice.

3. In fact, it is reality, and it is conjecture in theory.

4. Theory is generally based on reality and summarized according to reality. But sometimes it is divorced from reality, so theory and practice are not the same.

The difference between theory and practice, I will say that in general, there are some differences between theory and practice, and we have some of the main relationships.

Categories: Science & Engineering >> Engineering & Technology Sciences.

Problem description: A 100-watt 220-volt incandescent lamp theoretically has a resistance of 484 ohms, but in practice it is only 16 ohms. I don't know why? In addition, when it is connected to 220 volts in series with a forty-watt system, it does not light up.

This is probably known to everyone. But when I connected it in series with a 34 ohm resistive heating wire, the light came on. The resistance wire is not red, almost no heat, according to the reason that the partial voltage of the resistance wire is more, it should be the resistance heating, the 100 watt lamp is not lit is right, the actual question is:

Since the resistor wire is easy to burn under full voltage, so I want to connect a resistor current limit, I have tried to connect a 100 microfara capacitor in series, but I still burn the normally closed delay contact of the 5A time relay. I would be grateful for any expert to explain and guide! Resistance wires are used in hair dryers, analysis:

The theoretical resistance of a 100-watt 220-volt incandescent lamp is 484 ohms, which refers to the resistance of the incandescent lamp when it is on, that is, the resistance of the tungsten filament at high temperatures. This is the same as when you use a multimeter (tungsten filament at room temperature) only 16 ohms.

When the silver chain is connected to 220 volts in series with a 40 watt resistant, because the resistance of 40 watts is greater than that of 100 watts, the voltage obtained by 100 watts is less than 40 140 * 220 = 63v, so it is not bright.

When it is connected in series with a 34 ohm resistance heating wire, the resistance of the lamp should be calculated as 484 ohms, so the lamp is on. The resistance wire is no longer red.

If you connect the 34 ohm resistance wire to 220V full voltage, the current is about, and the resistance wire you use is in the hair dryer, you must know that this wax-resistant resistance wire can only work normally under the condition of forced air cooling. Otherwise, it is easy to burn out, and the series capacitor is useless and useful, either increase the resistance, preferably 100 ohms, or add a 10A contactor.

1.The theory must first be truly understood, and the way to test true understanding is to be able to repeat it in a way that both women and children know, rather than relying on jargon to open a façade.

2.The reality is a complex system, and the complex system needs to be abstracted and refined to resist pressure under the same conditions as the theory, that is, the theory is a black box, which requires you to illuminate the inside with the help of actual lights, so that you may be able to see what the path through the black box looks like.

3.Theories always have the limitations of the times, so being able to refine theories on the basis of reality, or put forward new abstract concepts, is also a process of cyclical spiral jumps.

All in all, theory is superior to practice, and practice is a way to test theory as both a means and an end.