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How to measure the apparent resistivity of soil
The method is as follows: to measure the soil resistivity, the most accurate method is the four point equidistant method. The small electrodes are embedded in the four small holes arranged in a straight line of the measured soil, the buried depth is B, and the linear interval is a. the test current I flows into the outer two electrodes, and the potential difference V between the inner two electrodes can be measured by the potential difference meter or high voltage meter
How much resistance is the length of a resistance wire with uniform thickness twice that of the original one
The resistance is quadrupled
Because the resistance is proportional to the length, the cross-sectional area is inversely proportional
It will be twice as long and double as long. After lengthening, it will definitely become thinner, the cross-sectional area will be half, and the resistance will be doubled, so it will be four times
The diameter of FeCr Al alloy resistance wire is 6 mm and the length is 15.5 M. what is the resistance of this resistance wire?
If the resistance is 0.8 Ω and the length is 15.5m, what is the diameter of the resistance wire?
The resistance of this resistance wire r = ρ L / S = (0.0000014) × 15.5 ^ (π × (6 ^ 2 ^ 1000) & # 178;) = 0.7675 Ω
A nickel chromium wire with uniform thickness is drawn into 1 / 10 of its original diameter and uniform thickness. How many times of its original resistance?
The diameter becomes 1 / 10 of the original, so the area becomes 1 / 100 of the original,
Because it is the same nickel chromium wire, the volume is constant, so the length becomes 100 times of the original, (v = L * s)
The resistance formula r = ρ L / s. therefore, the resistance becomes 100 * 100 = 10000 times of the original
RELATED INFORMATIONS
- 1. The resistance of a uniform wire will be cut into two equal sections and the two sections will be twisted together
- 2. A uniform thickness metal wire is stretched to twice the original length and cut into two sections, one of which is resistance A wire of uniform thickness is drawn twice as long as the original wire and cut into two sections from the middle, one of which has a resistance of -
- 3. When a uniform nickel chromium wire is drawn into a uniform wire of 110 in diameter, its resistance becomes n times of the original, then n is () A. 11000B. 1100C. 100D. 10000
- 4. When a student was doing the experiment of measuring the resistance of a small light bulb, he connected the circuit, closed the switch and found that the light bulb did not emit light (1) When doing the experiment of measuring the resistance of a small bulb, a student connected the circuit, closed the switch, and found that the bulb did not emit light, the ammeter showed the number, and the voltmeter did not show the number. After inspection, it was found that there was only a fault at the bulb, so the reason for the above phenomenon may be () (2) When doing the experiment of measuring the resistance of a small bulb, a student connected the circuit and closed the switch. He found that the bulb was not on, the ammeter did not show the number, and the voltmeter had a large number. The reason for the above phenomenon may be () Urgent, must tell me why, by the way, short circuit, open circuit and other differences
- 5. As shown in the figure, the voltage at both ends of the power supply does not change, and the resistance value of resistance R1 is 2 Ω. Close the switch S. when the slide P of sliding rheostat is at point a, the indication value of voltmeter V1 is 4V, and that of voltmeter V2 is 10V. When the slide P of sliding rheostat is at point B, the indication value of voltmeter V1 is 8V, and that of voltmeter V2 is 11V. Then the resistance value of resistance R2 is 4V___ Ω．
- 6. In the circuit shown in the figure, close the switch s and move the slide P of the sliding rheostat. When the indication of the voltmeter is 6V, the indication of the current is 0.5A; when the indication of the voltmeter is 7.2V, the indication of the ammeter is 0.3A. Then the resistance R0 is 0______ Ω, the power supply voltage is______ V．
- 7. As shown in the figure, the voltage at both ends of the power supply remains unchanged, and the resistance value of resistance R1 is 2 Ω. Close switch S. when slide P of sliding rheostat is located at point a, the indication value of voltmeter V1 is 4V, and that of voltmeter V2 is 10V. When slide p of sliding rheostat is located at point B, the indication value of voltmeter V1 is 8V, and that of voltmeter V2 is 11V______ W．
- 8. There is a DC power supply whose internal resistance can be neglected to deliver current to the series resistor A. B. when the 90 ohm resistor a is short circuited, the current in the circuit is four times that before the short circuited, then the resistance value of the resistor B is?
- 9. How to calculate the parallel resistance of an ammeter with a range of 100ua and an internal resistance of 1K Ω instead of 1.1ma
- 10. Junior high school physics electricity to explore the factors affecting the size of conductor resistance The resistance is related to the material, length and cross-sectional area of the conductor. I want a metaphor to make me understand it better For example, the cross-sectional area of a conductor is the thickness of the conductor. It is compared to a road. A wide road is more unobstructed than a narrow road, so the resistance with a thick cross-sectional area is smaller, so the brightness of the light bulb is brighter. I don't know how to understand the other two factors. If there is a metaphor, I don't want to memorize it
- 11. The grounding resistance of grounding device has nothing to do with soil resistivity Is that right? Can you explain why
- 12. What is the material with the lowest resistivity?
- 13. The total resistance of the transmission line between Party A and Party B is 10 Ω. The power to transmit electric energy from Party A to Party B is 11000 kW, and the transmission voltage is 220kV
- 14. Relationship between conductivity and resistance I use the conductance meter to measure the value of 3.03ms &; cm2. I want to convert it into. Ω &; cm2. What should it be and how to calculate it. Thank you
- 15. Conductivity unit: 1ms / cm = () us / cm
- 16. Why is the resistance in the electric pen very high?
- 17. What material is the resistance in the test pen?
- 18. What is the resistance of a 0 ohm resistor? Is it possible to reach one milliohm? Just want to know the exact range
- 19. The number measured by the 2000K ohm range of the multimeter is 900. Should the reading be 900K ohm or how much?
- 20. Unit conversion of resistance 1)400Ω=___ KΩ=___ MΩ 2)1.5KΩ=__ Ω=__ MΩ 3)16000Ω=_____ KΩ=_____ MΩ 4)0.3MΩ=___ KΩ=____ Ω Help. Thank you