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Anonymous users2024-02-07According to the resistivity equation, if the earth fully plays the role of a conductor (the contact area of the positive and negative electrodes is very large), the magnitude of the resistance should be inversely proportional to the magnification (the cube is like this, the circle should be approximate), you can shrink the earth into a ball with a radius of 1 meter, add the electrodes to the poles of the ball, and measure the resistance r, then when the ball is enlarged to the size of the earth, the resistance will be r 6400000, which is very small. It's a pity that you can't magnify the connectors and energizing devices of the positive and negative electrodes to 6,400,000 times the original, so their resistance is infinitely larger than the resistance of the earth, and you electrify the earth like putting two ultra-thin needles on both ends of the ball, how much current do you say will pass through? Moreover, the voltage you add and the current you pass through are also insignificant to the earth, and the current is also restricted by many factors such as the geomagnetic field, so you can't electrify the earth!
The junior high school knowledge solution is not entirely correct, but I think it can explain the problem.
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Anonymous users2024-02-06The two points on the earth should be taken from the corresponding points, such as the South Pole and the North Pole, but the problem with this is that the surface resistance cannot be shielded, because the oceans are connected, and the water is conductive.
This question ......
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Anonymous users2024-02-05You can set up a high-voltage line from the north and south poles to measure it, but be careful of the danger of high voltage when measuring...
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Anonymous users2024-02-04It's hard to say that the resistance is different from place to place.
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Anonymous users2024-02-03Does this question make sense? It doesn't seem to have any research value, does it?
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Anonymous users2024-02-02After the analysis and study of a large number of experimental data, it is determined that the average value of human resistance is generally about 2000, and when calculating and analyzing, the lower limit value is usually 1700. According to the formula, the resistance is 0 when the area of the earth is infinite.
The human body impedance is not a pure resistance and is mainly determined by the resistance of the human body. The resistance of the human body is also not a fixed value. It is generally believed that the dry ** has a fairly high resistance at low voltages, about 100,000 ohms.
When the voltage is 500 1000 volts, the resistance of the human body drops to 1000 ohms.
At a certain temperature, the resistance of a known object can be calculated from the resistivity, length l, and cross-cut area s of the world: the formula is r = l s, where l is the length of the dispersive fuel, and s is the area. It can be seen that the magnitude of the resistance of a material is directly proportional to the length of the material and inversely proportional to its cross-sectional area.
So the earth resistance is 0.
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Anonymous users2024-02-01The human body is 20k-200k, but it will be broken down under high voltage, and it is very small at this time. The earth acts as the negative pole of all power supplies without considering the resistance.
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Anonymous users2024-01-31Human body: It is generally believed to be at low voltage in the case of dryness.
There is a fairly high resistance value, about 100,000 ohms. When the voltage is between 500 and 1000 volts, the human body voltage drops to 1000 ohms.
Earth: Generally speaking, people would say that the resistance value is close to zero. You can think of it this way as an object with a very low resistance and a very large capacity.
He has the ability to absorb an infinite charge and still maintain the potential after absorption. Some junior high school teachers may say that because the earth absorbs electric charges infinitely, we approximate the resistance of the earth as infinity when we understand it, which is convenient to understand.
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