Why is the electrostatic current in tens of thousands of volts small?

There is no danger because the electricity q is very small, Q = it, because the time to generate static electricity is very short, so the electricity generated is very small, and the static electricity will indeed reach tens of thousands of volts, because the human eye can see the spark, indicating that the air has been broken down by high-voltage electricity, outside the safe voltage, whether there is any danger to the human body mainly depends on the amount of electricity that continues to flow through the body.

There is a deviation in the use of the landlord's formula, and in this case, we should not use Ohm's law but the formula ui=p. Since the power of static electricity is very small, when its voltage is very large, its current will of course become smaller. It is not the voltage but the current that causes harm to the human body, so if the current is small, it will not cause any harm to the human body.

The explanation of guwenkai007 is very reasonable, and we study whether a person's electric shock will cause danger in addition to looking at the size of the current, and the time of action of the current is also very important. The power itself is very small, and it doesn't pose much of a threat when it is done.

First of all, the current of static electricity is not much in the human body or some objects in contact with people, and the charge carried by those things is not much at all, so the current is not a big deal.

The question is a good one, and everyone can synthesize it above.

Who said that the human body often produces tens of thousands of volts of static electricity, if you were like this, you would have died a long time ago.

Who said that the body often produces static electricity tens of thousands of volts, there is no basis.

Under different humidity conditions, the electrostatic potential generated by human activity is different. In the dry season, the static electricity of the human body can reach thousands of volts or even tens of thousands of volts. Experiments have proved that there is no discomfort in the human body when the electrostatic voltage is 50,000 volts, and there is no danger to life when the electrostatic voltage is 120,000 volts.

As for why I think that high voltage does not necessarily mean high current, and it is only life-threatening when the human body flows through high current) However, electrostatic discharge also generates electromagnetic fields around it, which are of great intensity, although they last for a short time. Researchers are studying the effects of electrostatic electromagnetic fields on the human body.

The human body discharges electricity without knowing it, which is generally rare.

For example, the clothes worn by the human body carry static electricity, and they will discharge when they encounter conductive substances such as metals;

Categories: Education Science >> Science & Technology >> Engineering Technology Science Problem Description:

Why is the electrostatic voltage so large, but it will not cause fatal harm to the human body? What is the difference between electrostatic voltage and ordinary voltage?

Analysis: There is no difference between electrostatic voltage and ordinary voltage, and the difference between electrostatic and ordinary usable electricity is that ordinary usable electricity, such as electricity generated by power plants, is continuously delivered with constant current. Static electricity, because the amount of electricity that the object itself can hold when it is charged is too small, and this small amount of electricity cannot produce continuous current, so the current can only produce an instantaneous discharge with a very short time, because the discharge time is too short, and the amount of charge is too small, so it will not cause harm to the human body.

There are also electrostatic discharge phenomena that can cause harm to the human body, such as lightning. The reason why lightning can hurt people is because clouds are very large in size, so they can hold more electric charges, which can produce enough effects to hurt people.

First of all, the sweater has an electric charge for some reason.

Then we know that the voltage is another reference, the voltage we usually say, should be the voltage between what and what, so that it is accurate, then the voltage we are talking about here is the voltage between the sweater and the earth, then this voltage is coming. Because the sweater is slow to wither and charge, and the sweater has a certain gap with the earth - this constitutes the nearest component of the circuit - capacitor, it can be seen that this capacitance is very small u=q c In the case of a certain amount of electricity, a very small capacitor will produce a very high voltage! That's why another tens of thousands of volts of voltage.

How is the current generated, is Q t because it cannot provide a continuous charge, so the higher the voltage, the shorter the discharge time, and it may be a large current in an instant, but in general, the current disturbance is still very small.

In physics and in life, there is no fixed range of values for static electricity. In general industrial production, electrostatic electricity has the characteristics of high potential, low electricity, small current and short action time, and the electrostatic potential on the equipment or human body can reach up to tens of thousands of volts to hundreds of thousands of volts; Under normal operating conditions, it often reaches hundreds of volts to thousands of volts; This is much higher than the commercial low voltage 220V, 380V, but the accumulated electrostatic charge is very low, usually in the nanocoulomb (NC, 10-9C) range; The electrostatic current is mostly microampere (a, 10-6a) level, and the action time is mostly microsecond (s, 10-6s) level.

Those who say that the voltage is large and the current are small are guessing, just because the power-on time is too short.

The human body can be seen as pure electrical resistance because both inductive and capacitive are small. Since it is a pure resistor, then for a person, the lethal voltage and the lethal current are the same thing - if one is determined, the other can be calculated.

The cause of death from electrocution in humans is nerve spasm, which leads to myocardial infarction and suffocation of brain cells, which requires a certain amount of time to accumulate sufficient power. With the electrostatic voltage level generated by the friction of clothing, it is not enough to last only nanoseconds. 220 volts and lightning can kill because there is enough power to keep the power on for a sufficient time.

In fact, the electrostatic voltage of clothing friction can be very high, and the current can reach hundreds of amperes or even similar to lightning at the moment of discharge! But immediately after a few nanoseconds, it decays exponentially to zero.

Static electricity is an electric field produced by an electric charge stored on a live object. If the electric epoch on a charged object is q, and the capacitance formed between the object and the ground in the inner hall of the band is c, then the potential difference between the charged object and the ground (the voltage of the friend) is u, and the relationship between them is: u=q c.

It can be seen that even a small number of Qs can produce a high voltage when the single C ratio is small. The small amount of electricity that can be generated means the less current can be generated.

Static electricity is easy to have when wearing clothes in winter.

A large amount of charge accumulation produces static electricity.