Question

A horizontal length of current-carrying wire is suspended from two identical flexible leads that are under tension due to the weight of the wire. The wire is oriented at right angles to a uniform magnetic field that has a magnitude of 4 T and is directed out of the screen of the figure. The length Lof the wire is 5 cm and its mass mis 10 g. What current will produce a magnetic force on the wire that is just sufficient to remove the tension in the flexible leads, and which way is the current flowing through the wire? Current-carrying wire suspended from identical flexible leads SBO magnetic field (out of the screen) Ceiling 1, current-carrying wire L 0.18 A, current flows left to right 0.18 A, current flows right to left 0.45 A, current flows left to right 0.25 A, current flows right to left 0.25 A, current flows left to right

Answer 1

Magnetic field, B = 4 T

Length of the wire, L = 0.05 m

Mass of the wire, m = 0.010 kg

Weight of the wire, W = mg = 0.01 x 9.8 = 0.098 N

Let I be current in the wire so that the magnetic force on the wire is equal to its weight.

Magnetic force, F = I L B

But, F = W

I L B = 0.098

Current, I = 0.098 /L B = 0.098 / 0.05 x 4 = 0.49 A

** 0.49 A current flow to the left.

Please note:

The current 0.49 A obtained with the given data is correct but this current is not given as an option. Please check the data or the options.