**Correct Option: B. Perpendicular to both the current and the magnetic field** ### Detailed Explanation: To understand the direction of the magnetic force experienced by a straight conductor carrying current in a magnetic field, we can use the right-hand rule, which is a helpful mnemonic in physics. 1. **Understanding the Right-Hand Rule**: - The right-hand rule states that if you point your thumb in the direction of the current (I) and your fingers in the direction of the magnetic field (B), then your palm will face in the direction of the magnetic force (F) acting on the conductor. - This rule is based on the cross product of the current vector and the magnetic field vector, which mathematically describes how the force is determined. 2. **Magnetic Force on a Current-Carrying Conductor**: - The magnetic force (F) on a straight conductor carrying current in a magnetic field can be calculated using the formula: \[ F = I \cdot L \cdot B \cdot \sin(\theta) \] where: - \( F \) is the magnetic force, - \( I \) is the current, - \( L \) is the length of the conductor, - \( B \) is the magnetic field strength, - \( \theta \) is the angle between the direction of the current and the magnetic field. - When the conductor is placed perpendicular to the magnetic field (i.e., \( \theta = 90^\circ \)), the sine function equals 1, and the force is maximized. 3. **Direction of the Force**: - Since the force is determined by the cross product of the current and the magnetic field, it is always perpendicular to both the current and the magnetic field. This means that the magnetic force does not act in the same direction as the current or the magnetic field but rather at a right angle to both. ### Why Other Options Are Incorrect: - **Option A: Parallel to the direction of the current**: - This option is incorrect because the magnetic force is not aligned with the current. Instead, it is perpendicular to the current, as established by the right-hand rule. - **Option C: In the same direction as the magnetic field**: - This option is also incorrect. The magnetic force does not follow the direction of the magnetic field; it is perpendicular to it. The force acts at a right angle to both the current and the magnetic field. - **Option D: Opposite to the direction of the current**: - This option is misleading. While the force can be in the opposite direction to the current in some configurations, it is not a general rule. The force is always perpendicular to the current, not necessarily opposite. ### Summary of Key Points: - The magnetic force on a current-carrying conductor in a magnetic field is determined using the right-hand rule. - The force is always **perpendicular** to both the direction of the current and the magnetic field. - The formula for calculating the magnetic force involves the current, length of the conductor, magnetic field strength, and the angle between the current and the magnetic field. - Understanding the right-hand rule is crucial for determining the direction of the magnetic force in various scenarios. This thorough understanding of the magnetic force on a current-carrying conductor will help you apply these concepts in various physics problems and scenarios.