Question

Алюминиевый провод длиной 200 метров подключён к источнику тока,напряжение на котором составляет 1,4В .Сила тока в проводе равна 0,5А .Какова площадь поперечного сечения провода?

Answer 1

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Answer 2

Calculation of the Cross-Sectional Area of the Aluminum Wire

To calculate the cross-sectional area of the aluminum wire, we can use the formula:

Area = Current / (Resistance × Current Density)

In this case, we are given the following information: - Length of the wire (l) = 200 meters - Voltage (V) = 1.4V - Current (I) = 0.5A

To calculate the resistance, we can use Ohm's Law:

Resistance = Voltage / Current

Let's calculate the resistance first:

Resistance = 1.4V / 0.5A = 2.8Ω Now, we need to determine the current density. Unfortunately, the current density is not provided in the given information. However, we can assume a typical value for the current density of aluminum, which is around 5 × 10^6 A/m^2.

Using the formula for the cross-sectional area, we can rearrange it to solve for the area:

Area = Current / (Resistance × Current Density)

Substituting the given values:

Area = 0.5A / (2.8Ω × 5 × 10^6 A/m^2)

Calculating the area:

Area ≈ 0.0357 mm^2

Therefore, the approximate cross-sectional area of the aluminum wire is 0.0357 mm^2.

Please note that this calculation assumes a uniform current distribution and does not take into account any other factors that may affect the wire's resistance or current density.