Question

Как определить длинну медного провода в метке,если его нельзя размматывать?Провод имеето круглое сечение.Какие приборы для этого потребуются?

Answer 1

2 способа
1) штангельциркуль-измерить диаметр, весы-измерить массу
L=4*m/pπd²  p-плотность меди
2) штангельциркуль-измерить диаметр, Омметр - измерить сопротивление
L=Rd²/4p   p- удельное сопротивление меди

Answer 2

Determining the Length of a Copper Wire Without Unwinding

If you need to determine the length of a copper wire without unwinding it, there are a few methods and tools that can be used for this purpose.

Method 1: Measuring Resistance

One common method is to measure the resistance of the wire and use this value to calculate the length. The resistance of a wire is directly proportional to its length, so by measuring the resistance and knowing the wire's cross-sectional area and resistivity, the length can be calculated using the formula:

Length = Resistance / (Cross-sectional area * Resistivity)

To measure the resistance, you will need a multimeter, which is a versatile tool commonly used for measuring resistance, voltage, and current in electrical circuits.

Method 2: Using a Cable Length Meter

Another method is to use a cable length meter, also known as a distance measuring device. This tool is specifically designed for measuring the length of cables and wires without the need to unwind them. Cable length meters use various techniques such as capacitance measurement or time domain reflectometry to determine the length of the cable.

Method 3: Laser Distance Measurement

In some cases, laser distance measurement devices can also be used to indirectly measure the length of a wire. By carefully positioning the laser and measuring the distance to various points on the wire, the length can be calculated using trigonometric principles.

Conclusion

In summary, to determine the length of a copper wire without unwinding it, you can use methods such as measuring resistance with a multimeter, using a cable length meter, or employing laser distance measurement techniques. Each method requires specific tools and techniques, and the choice of method may depend on the available equipment and the accuracy required for the measurement.