A flat coil has a maximum flux of 4.0 × 10^-3 T·m² through it, with its area perpendicular to a uniform magnetic field. When the coil is rotated 60^° (so that its normal makes a 60^° angle with the field), what is the flux through it? A) 4.0 × 10^-3 T·m² B) 8.0 × 10^-3 T·m² C) 3.5 × 10^-3 T·m² D) 2.0 × 10^-3 T·m² E) 6.9 × 10^-3 T·m²

Question

Quizplus · Accepted Answer

The magnetic flux through a coil is given by $\Phi = B \cdot A \cdot \cos(\theta)$, where $B$ is the magnetic field strength, $A$ is the area of the coil, and $\theta$ is the angle between the magnetic field and the normal to the coil. At $60^\circ$, $\cos(60^\circ) = 0.5$. Therefore, the flux is halved from its maximum value of $4.0 \times 10^{-3} \, \text{T}\cdot\text{m}^2$, resulting in $2.0 \times 10^{-3} \, \text{T}\cdot\text{m}^2$.

A Flat Coil Has a Maximum Flux of 4