Question 548 of 949
What is the direction of the magnetic force experienced by a current-carrying conductor placed in a magnetic field, according to the right-hand rule?
- Parallel to the direction of the magnetic field
- Opposite to the direction of the current
- Perpendicular to both the current and the magnetic field
- In the same direction as the current
Correct Answer:
C
Explanation
### Correct Option: C. Perpendicular to both the current and the magnetic field
### Detailed Explanation:
To understand the direction of the magnetic force experienced by a current-carrying conductor in a magnetic field, we can use the **right-hand rule**. This rule is a helpful mnemonic that allows us to visualize the relationship between the direction of the current, the magnetic field, and the resulting magnetic force.
#### Step-by-Step Explanation:
1. **Identify the Components**:
- **Current (I)**: This is the flow of electric charge through the conductor, typically represented by the direction in which positive charges would move.
- **Magnetic Field (B)**: This is the field created by magnets or by electric currents, represented by field lines that indicate the direction of the magnetic force on a north pole.
2. **Using the Right-Hand Rule**:
- Extend your right hand.
- Point your thumb in the direction of the **current** (I).
- Point your fingers in the direction of the **magnetic field** (B).
- Your palm will then face in the direction of the **magnetic force** (F) acting on the conductor.
3. **Conclusion**:
- According to the right-hand rule, the magnetic force is always **perpendicular** to both the direction of the current and the direction of the magnetic field. This means that if you have a current flowing in a wire and a magnetic field applied, the force will act at a right angle to both of these directions.
### Why Other Options Are Incorrect:
- **Option A: Parallel to the direction of the magnetic field**:
- This option is incorrect because the magnetic force cannot be parallel to the magnetic field. The force is always perpendicular to the magnetic field lines, as established by the right-hand rule.
- **Option B: Opposite to the direction of the current**:
- This option is also incorrect. The magnetic force does not act in the opposite direction of the current. Instead, it acts perpendicular to the current's direction, as indicated by the right-hand rule.
- **Option D: In the same direction as the current**:
- This option is incorrect as well. The magnetic force is not in the same direction as the current. Again, it is perpendicular to the current's direction, which is a fundamental aspect of how magnetic forces operate on current-carrying conductors.
### Formulas and Concepts:
- The magnetic force \( F \) on a current-carrying conductor 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 in the magnetic field,
- \( B \) is the magnetic field strength,
- \( \theta \) is the angle between the direction of the current and the magnetic field.
- When the current and magnetic field are perpendicular (\( \theta = 90^\circ \)), \( \sin(90^\circ) = 1 \), and the formula simplifies to:
\[
F = I \cdot L \cdot B
\]
### Common Pitfalls:
- **Misunderstanding the Right-Hand Rule**: Students often confuse the directions of the thumb and fingers. Remember, the thumb represents the current, and the fingers represent the magnetic field.
- **Forgetting the Perpendicular Relationship**: Itβs crucial to remember that the magnetic force is always perpendicular to both the current and the magnetic field, which is a key concept in electromagnetism.
### Revision Summary:
- The magnetic force on a current-carrying conductor is **perpendicular** to both the current and the magnetic field.
- Use the **right-hand rule**: Thumb (current), fingers (magnetic field), palm (force).
- The formula for magnetic force is \( F = I \cdot L \cdot B \cdot \sin(\theta) \).
- Always remember the relationship between current, magnetic field, and force to avoid common mistakes.