In order to determine the length of the wire, use the following formula for the force exterded on a wire in a magnetic field:
[tex]F=I\cdot L\cdot B\cdot\sin \theta[/tex]where,
I: current through the wire = 2.0A
L: length of the wire = ?
B: strength of magnetic field = 0.20T
θ: angle between the axis of the wire and the direction of B = 60 degrees
F: force = 0.40N
Solve the equation above for L, replace the values of the other parameters and simplify:
[tex]\begin{gathered} L=\frac{F}{I\cdot B\cdot\sin \theta} \\ L=\frac{0.40N}{(2.0A)(0.20T)\sin 60} \\ L\approx1.15m \end{gathered}[/tex]Hence, the length of the wire is approximately 1.15m
