Final answer:
The force between the hot and neutral wires supplying DC power to a train is approximately 3.6 N. Therefore, the correct option is b).
Step-by-step explanation:
To calculate the force between two parallel wires carrying a direct current (DC), we can use the equation:
F = (μ₀ * I₁ * I₂ * L) / (2 * π * d)
Where:
- F is the force between the wires
- μ₀ is the permeability of free space (4π x 10^-7 T·m/A)
- I₁ and I₂ are the currents in the wires (in this case, 800 A)
- L is the length of the wires (50.0 m)
- d is the separation between the wires (75.0 cm = 0.75 m)
Plugging in these values, we get:
F = (4π x 10^-7 T·m/A) * (800 A) * (800 A) * (50.0 m) / (2π * 0.75 m)
Simplifying the equation, we find that the force between the wires is approximately 3.6 N.