Question

МАКСИМУМ БАЛЛОВ определите массу железной проволоки площадью попереченого сечения 2мм^2 , взятой для изготовления реостата ,рассчитанного на прохождение по нему тока 1 А при напряжения 6В

Answer 1

1 R=U/I=6/1=6 OM
2 R=рэ*L/S L=R*s/рэ=6*2/12*10-2=100м
3 m=p*s*L=7800*2*10-6*100=1.56 кг

Answer 2

Calculating the Mass of Iron Wire for a Rheostat

To calculate the mass of the iron wire required for the rheostat, we can use the formula:

Resistance (R) = (resistivity x length) / cross-sectional area

Given: - Current (I) = 1 A - Voltage (V) = 6 V - Cross-sectional area (A) = 2 mm^2

We can rearrange the formula to solve for the length of the wire: Length (L) = (Resistance x cross-sectional area) / resistivity

Then, we can use the formula for the resistance of a wire: Resistance (R) = (resistivity x length) / cross-sectional area

Let's calculate the mass of the iron wire step by step.

1. Calculate the Resistance (R): - Using Ohm's Law: R = V / I - Substituting the given values: R = 6 Ω

2. Calculate the Length (L) of the Wire: - Using the formula: L = (R x A) / ρ - Where ρ (rho) is the resistivity of iron, which is approximately 9.71 x 10^-8 Ωm.

   L = (6 Ω x 2 x 10^-6 m^2) / (9.71 x 10^-8 Ωm)
   L ≈ 1.24 x 10^3 m
   

3. Calculate the Mass of the Wire: - Using the formula: mass = volume x density - The volume of the wire can be calculated using the formula: volume = cross-sectional area x length - The density of iron is approximately 7,870 kg/m^3.

   volume = 2 x 10^-6 m^2 x 1.24 x 10^3 m
   volume ≈ 2.48 x 10^-3 m^3

mass = 2.48 x 10^-3 m^3 x 7,870 kg/m^3
   mass ≈ 19.56 kg
   

Therefore, the mass of the iron wire required for the rheostat is approximately 19.56 kg.