A copper wire of length 25.0 cm is in a magnetic field of 0.36 T.If it has a mass of 11.0 g,what is the minimum current through the wire that would cause a magnetic force equal to its weight?

Question

Quizplus · Accepted Answer

The magnetic force on a current-carrying wire is given by $F = BIL$, where $F$ is the force, $B$ is the magnetic field strength, $I$ is the current, and $L$ is the length of the wire. The weight of the wire, which is the force due to gravity, is given by $W = mg$, where $m$ is the mass and $g$ is the acceleration due to gravity (approximately $9.8 \, \text{m/s}^2$). Setting the magnetic force equal to the weight gives $BIL = mg$. Solving for $I$ gives $I = \frac{mg}{BL}$.Substituting the given values: $m = 0.011 \, \text{kg}$, $B = 0.36 \, \text{T}$, $L = 0.25 \, \text{m}$, and $g = 9.8 \, \text{m/s}^2$, we get:$$I = \frac{0.011 \times 9.8}{0.36 \times 0.25} = \frac{0.1078}{0.09} = 1.2 \, \text{A}$$

A Copper Wire of Length 25