### Correct Option: A. Upward ### Detailed Explanation: To determine the direction of the magnetic force experienced by a current-carrying wire in a magnetic field, we can use the **right-hand rule**. This rule is a helpful mnemonic for visualizing the relationship between the direction of the current, the magnetic field, and the resulting magnetic force. 1. **Identify the Directions**: - **Current Direction**: The current is flowing from left to right. - **Magnetic Field Direction**: The magnetic field is directed into the page. 2. **Applying the Right-Hand Rule**: - **Step 1**: Extend your right hand. - **Step 2**: Point your thumb in the direction of the current (from left to right). - **Step 3**: Point your fingers in the direction of the magnetic field (into the page). - **Step 4**: Your palm will face upward, indicating the direction of the magnetic force. 3. **Conclusion**: According to the right-hand rule, the magnetic force acting on the wire will be directed **upward**. ### Why Other Options Are Incorrect: - **Option B: Downward**: This option suggests that the magnetic force is directed downward. However, according to the right-hand rule, if you follow the steps correctly, the palm faces upward, not downward. Therefore, this option is incorrect. - **Option C: Out of the page**: This option implies that the force is directed out of the page towards the observer. Again, using the right-hand rule, the force is not directed out of the page when the current flows left to right and the magnetic field is into the page. Thus, this option is also incorrect. - **Option D: Into the page**: This option suggests that the force is directed into the page. However, as established through the right-hand rule, the force is directed upward, not into the page. Therefore, this option is incorrect as well. ### Formulas and Concepts: The magnetic force \( F \) on a current-carrying wire can be calculated using the formula: \[ F = I \cdot L \cdot B \cdot \sin(\theta) \] Where: - \( F \) = magnetic force (in Newtons) - \( I \) = current (in Amperes) - \( L \) = length of the wire in the magnetic field (in meters) - \( B \) = magnetic field strength (in Teslas) - \( \theta \) = angle between the current direction and the magnetic field direction In this case, since the current and magnetic field are perpendicular to each other (90 degrees), \( \sin(90^\circ) = 1 \), simplifying the formula to: \[ F = I \cdot L \cdot B \] ### Common Pitfalls: - **Misapplying the Right-Hand Rule**: It's crucial to remember that the thumb represents the current, the fingers represent the magnetic field, and the palm indicates the direction of the force. - **Forgetting the Angle**: If the current and magnetic field are not perpendicular, you must consider the angle in the sine function. - **Confusing Directions**: Always double-check the directions of the current and magnetic field before applying the right-hand rule. ### Revision Summary: - Use the right-hand rule to determine the direction of the magnetic force on a current-carrying wire. - Current flowing left to right and a magnetic field into the page results in an upward force. - The formula for magnetic force is \( F = I \cdot L \cdot B \cdot \sin(\theta) \). - Be cautious of common pitfalls, especially in applying the right-hand rule and understanding the angle between current and magnetic field.