Question

Чему равна сила тока, проходящая через реостат, изготовленный из железной проволоки длиной 68 м и площадью поперечного сечения 2,7 мм², если напряжение на зажимах реостата — 98 В?

Answer 1

Відповідь:

39,2А

Пояснення:

Знайдемо еквівалентний опір залізного реостату:R=β*L/S⇒0.098*68/2.7=2.5(Om)

  I=U/R⇒98/2.5=39.2(A)

Answer 2

Calculation of Current through the Resistor

To calculate the current passing through a resistor, we can use Ohm's Law, which states that the current (I) flowing through a conductor is equal to the voltage (V) across the conductor divided by the resistance (R) of the conductor. Mathematically, it can be represented as:

I = V / R

In this case, we are given the voltage across the resistor (V = 98 V) and we need to find the current passing through the resistor. However, we are not provided with the resistance value directly. Instead, we are given the length and cross-sectional area of the iron wire used to make the resistor.

To find the resistance of the wire, we can use the formula:

R = (ρ * L) / A

Where: - R is the resistance of the wire - ρ (rho) is the resistivity of the material (in this case, iron) - L is the length of the wire - A is the cross-sectional area of the wire

The resistivity of iron is a material property and can be found in reference tables. For simplicity, we will assume a resistivity value of 9.71 x 10^-8 Ω·m for iron.

Now, let's substitute the given values into the formula to find the resistance:

R = (9.71 x 10^-8 Ω·m * 68 m) / (2.7 x 10^-6 m²)

Calculating this expression will give us the resistance of the wire.

Calculation Steps:

1. Multiply the resistivity of iron (9.71 x 10^-8 Ω·m) by the length of the wire (68 m). 2. Divide the result by the cross-sectional area of the wire (2.7 x 10^-6 m²). 3. Calculate the final result.

Please note that the resistivity value used here is an approximation and may not be entirely accurate. Additionally, the given snippet does not provide the resistivity value, so we are assuming a standard value for iron.

Let's calculate the resistance and then use Ohm's Law to find the current passing through the resistor.