In this example, we analyze a rectangular current loop with dimensions of 4 meters wide and 2 meters deep, resulting in an area of 8 square meters. The loop is positioned in a constant magnetic field of 5 T (Tesla), which is directed at an angle of 30 degrees above the horizontal plane. Understanding the orientation of the loop and the magnetic field is crucial, as the loop is parallel to the plane, meaning it lies flat on the floor.
To determine the current flowing through the loop, we utilize the torque equation. The net torque (\( \tau \)) experienced by the loop is given as 10 N·m. The relevant formula for torque in this context is:
\[ \tau = n \cdot B \cdot A \cdot I \cdot \sin(\theta) \]
Where:
- \( n \) = number of loops (assumed to be 1 in this case)
- \( B \) = magnetic field strength (5 T)
- \( A \) = area of the loop (8 m²)
- \( I \) = current (unknown)
- \( \theta \) = angle between the normal to the loop's surface and the magnetic field direction
To find the angle \( \theta \), we note that the normal to the surface of the loop points directly upward, while the magnetic field is at a 30-degree angle above the plane. Therefore, the angle we need to use in our calculations is \( 90^\circ - 30^\circ = 60^\circ \).
Rearranging the torque equation to solve for current \( I \), we have:
\[ I = \frac{\tau}{n \cdot B \cdot A \cdot \sin(\theta)} \]
Substituting the known values:
\[ I = \frac{10}{1 \cdot 5 \cdot 8 \cdot \sin(60^\circ)} \]
Calculating \( \sin(60^\circ) \) gives approximately \( 0.866 \), leading to:
\[ I = \frac{10}{40 \cdot 0.866} \approx 0.29 \text{ A} \]
Thus, the current flowing through the loop is approximately 0.30 A. While the direction of the current is not specified, understanding the torque and magnetic field orientation is essential for further analysis in electromagnetic applications.