Question

К концам нихромовой проаолки сечением 0.5 мм и длинной 6м подано напряжение 40В.Определите силу тока в проволке

Answer 1

J=U/R
R=p*l/s=13,2 Ом
J=40/13,2=3,03 А.

Answer 2

Calculating Current in a Nichrome Wire

To calculate the current in a nichrome wire with a cross-sectional area of 0.5 mm² and a length of 6m when a voltage of 40V is applied, we can use Ohm's law.

Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points. The formula is given by:

I = V / R

Where: - I = Current (in amperes, A) - V = Voltage (in volts, V) - R = Resistance (in ohms, Ω)

Calculating Resistance

First, we need to calculate the resistance of the nichrome wire using the formula:

R = ρ * (L / A)

Where: - R = Resistance (in ohms, Ω) - ρ = Resistivity of the material (in ohm-meter, Ωm) - L = Length of the wire (in meters, m) - A = Cross-sectional area of the wire (in square meters, m²)

Resistivity of Nichrome

The resistivity of nichrome can be found in the literature or online sources. For the purpose of this calculation, let's assume the resistivity of nichrome is 1.10 × 10^-6 Ωm.

Calculating Resistance

Using the resistivity of nichrome and the given length and cross-sectional area, we can calculate the resistance of the wire.

R = (1.10 × 10^-6) * (6 / 0.5) R = 13.2 Ω

Calculating Current

Now that we have the resistance, we can use Ohm's law to calculate the current.

I = V / R I = 40 / 13.2 I ≈ 3.03 A

Therefore, the current in the nichrome wire is approximately 3.03 amperes when a voltage of 40V is applied.