Question 547 of 949
A straight conductor carrying a current of 5 A is placed in a uniform magnetic field of strength 0.2 T. If the length of the conductor within the magnetic field is 0.5 m and it is oriented perpendicular to the magnetic field, what is the magnitude of the magnetic force acting on the conductor?
Correct Answer:
B
Explanation
To determine the magnitude of the magnetic force acting on a straight conductor carrying a current in a magnetic field, we can use the formula:
\[
F = BIL \sin(\theta)
\]
Where:
- \( F \) is the magnetic force (in Newtons, N),
- \( B \) is the magnetic field strength (in Teslas, T),
- \( I \) is the current (in Amperes, A),
- \( L \) is the length of the conductor within the magnetic field (in meters, m),
- \( \theta \) is the angle between the direction of the current and the direction of the magnetic field.
### Step-by-Step Calculation
1. **Identify the Given Values**:
- Current, \( I = 5 \, \text{A} \)
- Magnetic field strength, \( B = 0.2 \, \text{T} \)
- Length of the conductor, \( L = 0.5 \, \text{m} \)
- Orientation: The conductor is perpendicular to the magnetic field, so \( \theta = 90^\circ \).
2. **Calculate the Sine of the Angle**:
- Since the conductor is perpendicular to the magnetic field, \( \sin(90^\circ) = 1 \).
3. **Substitute the Values into the Formula**:
\[
F = BIL \sin(\theta) = (0.2 \, \text{T}) \times (5 \, \text{A}) \times (0.5 \, \text{m}) \times 1
\]
4. **Perform the Calculation**:
\[
F = 0.2 \times 5 \times 0.5 = 0.5 \, \text{N}
\]
### Conclusion
The magnitude of the magnetic force acting on the conductor is **0.5 N**. Therefore, the correct option is **A**.
### Explanation of Other Options
- **Option B (1.0 N)**: This option is incorrect because it suggests that the force is double the calculated value. This could arise from a misunderstanding of the formula or miscalculating the product of the values.
- **Option C (1.5 N)**: This option is also incorrect. It does not correspond to any logical combination of the given values and indicates a significant miscalculation.
- **Option D (2.0 N)**: This option is incorrect as well. It suggests an even larger force, which is not supported by the values provided.
### Common Pitfalls
- **Misunderstanding the Angle**: Always ensure that the angle used in the sine function corresponds to the actual orientation of the conductor relative to the magnetic field.
- **Forgetting to Use the Correct Units**: Ensure that all values are in the correct units (A for current, T for magnetic field strength, m for length).
- **Neglecting the Sine Function**: If the angle is not 90 degrees, remember to calculate the sine of the angle correctly.
### Revision Summary
- Use the formula \( F = BIL \sin(\theta) \) to calculate the magnetic force.
- Ensure the angle \( \theta \) is correctly identified; \( \sin(90^\circ) = 1 \) for perpendicular orientation.
- Substitute the values carefully and perform the multiplication step-by-step.
- Double-check calculations to avoid common pitfalls related to angles and units.