Question

A $2.00m$ length of wire carrying $3.00A$ of conventional current southward through a $5.00T$ magnetic field directed straight up experience how much force due the field and in what direction?

• A. Amount of Force -$7.5N$, Direction of Force - west
• B. Amount of Force -$30.0N$, Direction of Force - west
• C. Amount of Force -$7.5N$, Direction of Force - east
• D. Amount of Force -$30.0N$, Direction of Force - east
• E. Amount of Force -$3.33N$, Direction of Force - north

Answer 1

Answer: (B)

Amount of Force -$30.0N$, Direction of Force - west

From figure, $\overrightarrow{l}=2.00$ $\hat{z}$ $\overrightarrow{B}=5.00$ $\hat{y}$ $I=3.00$ A

Magnetic force on the wire $\overrightarrow{F}=I(\overrightarrow{l}\times \overrightarrow{B})$

$\therefore$ $\overrightarrow{F}=3.00(2.00\hat{z}\times 5.00\hat{y})=30.0$ $(-\hat{x})$ Newtons

Thus magnetic force of $30$ Newtons acts in the West direction.