Permanent Magnet Field Calculator

Magnetic Field Formula:

\[ B = \frac{\mu_0 \cdot \mu}{2 \pi \cdot r^3} \]

Magnetic Field (B):

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1. What is a Permanent Magnet Field Calculator?

Definition: This calculator estimates the magnetic field strength (B) generated by a permanent magnet at a certain distance.

Purpose: It helps engineers, physicists, and students determine the magnetic field strength for various applications.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ B = \frac{\mu_0 \cdot \mu}{2 \pi \cdot r^3} \]

Where:

\( B \) — Magnetic field strength (Tesla)
\( \mu_0 \) — Permeability of free space (4π × 10⁻⁷ T·m/A)
\( \mu \) — Magnetic moment (A·m²)
\( r \) — Distance from magnet (meters)

Explanation: The magnetic field strength decreases with the cube of the distance from the magnet.

3. Importance of Magnetic Field Calculation

Details: Accurate field calculations are crucial for designing magnetic systems, sensors, and understanding magnetic interactions.

4. Using the Calculator

Tips: Enter the magnetic moment in A·m² and distance in meters. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is magnetic moment?
A: Magnetic moment (μ) measures a magnet's strength and orientation. For a bar magnet, μ = m × l, where m is pole strength and l is length.

Q2: Why does distance have such a strong effect?
A: The field strength follows an inverse cube law (1/r³), meaning it decreases rapidly with distance.

Q3: What's the permeability of free space?
A: μ₀ is a physical constant equal to 4π × 10⁻⁷ T·m/A (approximately 1.2566 × 10⁻⁶).

Q4: Can this be used for electromagnets?
A: This formula works best for permanent magnets or dipole fields. Electromagnets may require different calculations.

Q5: How accurate is this calculation?
A: This gives the theoretical field strength for an ideal dipole. Real magnets may vary due to shape, size, and material factors.