Two parallel,straight wires are 7.0 cm apart and each carries a 18.0 A current in the same direction.One wire is securely anchored,and the other is attached in the center to a movable cart.If the force needed to move the wire when it is not attached to the cart is negligible,with what force does the wire pull on the cart? Both wires are 50.0 m long.
A)4600 dynes
B)370 dynes
C)660 dynes
D)9300 dynes

Question

Quizplus · Accepted Answer

The force between two parallel wires carrying current in the same direction is given by:F = (μ0 * I1 * I2 * L) / (2π * d)where:μ0 is the permeability of free space (4π x 10^-7 T·m/A)I1 and I2 are the currents in the wires (18.0 A)L is the length of the wires (50.0 m)d is the distance between the wires (7.0 cm = 0.07 m)Plugging in the values, we get:F = (4π x 10^-7 T·m/A * 18.0 A * 18.0 A * 50.0 m) / (2π * 0.07 m)F = 4600 dynesTherefore, the force with which the wire pulls on the cart is 4600 dynes.

Two Parallel,straight Wires Are 7