A piece of wire with mass per unit length 88 g/m runs horizontally at right angles to a horizontal magnetic field. A 6.5A current in the wire results in its being suspended against gravity.

Question

A piece of wire with mass per unit length 88 g/m runs horizontally at right angles to a horizontal magnetic field. A 6.5A current in the wire results in its being suspended against gravity.
What is the magnetic field strength?
Express your answer using two significant figures.
  B =    T

bobpursley · Accepted Answer

force= mg= ILB mg/IL = B m/L is given as .088kg/meter g is well known I is given.

Anonymous · Answer

Use the equation F=IL X B that relates force on a current in a magnetic field.

Knowing the mass of the wire (.08)kg and the acceleration due to grav (9.8m/s^2) relate the two forces and solve for the variable B.

Because the cross product of L and B is 1 the relation is pretty simple.

(9.8)(.08)=5.8B