Question 550 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 angle between the conductor and the magnetic field is 30 degrees, what is the magnitude of the magnetic force acting on the conductor?
Correct Answer:
B
Explanation
To find 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 in the magnetic field (in meters, m),
- \( \theta \) is the angle between the conductor and the magnetic field (in degrees or radians).
### Step-by-Step Explanation
1. **Identify the Given Values**:
- Current, \( I = 5 \, \text{A} \)
- Magnetic field strength, \( B = 0.2 \, \text{T} \)
- Angle, \( \theta = 30^\circ \)
2. **Determine the Length of the Conductor**:
- The problem does not specify the length of the conductor, \( L \). However, we can assume that the length is 1 meter for the purpose of calculating the force per unit length. This is a common approach in physics problems unless otherwise stated.
3. **Calculate the Sine of the Angle**:
- We need to find \( \sin(30^\circ) \). From trigonometric values, we know:
\[
\sin(30^\circ) = 0.5
\]
4. **Substitute the Values into the Formula**:
- Now we can substitute the values into the formula:
\[
F = BIL \sin(\theta) = (0.2 \, \text{T}) \times (5 \, \text{A}) \times (1 \, \text{m}) \times \sin(30^\circ)
\]
\[
F = (0.2) \times (5) \times (1) \times (0.5)
\]
5. **Perform the Calculation**:
- Calculate the product step-by-step:
\[
F = 0.2 \times 5 = 1.0
\]
\[
F = 1.0 \times 1 = 1.0
\]
\[
F = 1.0 \times 0.5 = 0.5 \, \text{N}
\]
### 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 value is incorrect because it does not account for the sine of the angle. The force is halved due to the angle being 30 degrees.
- **Option C (1.5 N)**: This option is also incorrect as it suggests a higher force than what is calculated. It does not follow from the formula with the given values.
- **Option D (2.0 N)**: This option is incorrect as it implies a force that is not supported by the calculations. It does not consider the angle's effect on the force.
### Revision Summary
- Use the formula \( F = BIL \sin(\theta) \) to calculate magnetic force.
- Remember to convert angles to sine values when calculating.
- If the length of the conductor is not given, assume it to be 1 meter for calculations.
- Always check the units to ensure they are consistent (N, T, A, m).