Two wires, 2.44 m apart, both carry current 2.2 A toward the bottom of the screen. The right wire is extremely long, and the left wire is 0.36 m long. What is the magnetic force on the left wire?
Magnetic force, F = BIL --------(1) where B is the magnetic flux density of the magnetic field caused by the right wire, acting perpendicularly to the left wire in Tesla I is the current in the left wire in Amperes L is the length of the left wire in metres To find B (due to the right wire), you have to use the formula B = (?0)(I)/(2πr) -----(2) where the I in this case is the current in the right wire, r is the distance between the two wires, and ?0 is the permeability of free space, numerically defined as ?0 = 4π×10?7 using eqn (2) so B (due to right wire) = (?0x2.2)/(2πx2.44) = 1.8x10^-7 T using eqn (1) and the value of B calculated above F = (1.8x10^-7 x 2.2 x 0.36) = 1.43x10-7 N
