Magnetic Field Strength Converter
Convert between various units of magnetic field strength, including tesla, gauss, weber per square meter, and more.
About Magnetic Field Strength Units
Magnetic field strength, also known as magnetic flux density or magnetic induction, is a vector quantity that describes the intensity and direction of a magnetic field. The SI unit of magnetic field strength is the tesla (T), which is defined as one weber of magnetic flux per square meter.
Common Magnetic Field Strength Units
- Tesla (T): The SI unit of magnetic flux density. One tesla equals one weber per square meter (Wb/m²). Named after physicist Nikola Tesla.
- Gauss (G): A CGS unit of magnetic flux density. 1 gauss = 10-4 tesla. Named after mathematician and physicist Carl Friedrich Gauss.
- Milligauss (mG): Equal to 10-3 gauss or 10-7 tesla. Often used to measure weak environmental magnetic fields.
- Microtesla (μT): Equal to 10-6 tesla or 10-2 gauss. Used for measuring Earth's magnetic field and weak magnetic fields.
- Weber per square meter (Wb/m²): Equivalent to tesla. Used to emphasize the relationship with magnetic flux.
- Gamma (γ): Equal to 10-9 tesla or 10-5 gauss. Used in geophysical and space physics applications.
Magnetic Field and Magnetic Flux
Magnetic flux (Φ) through a surface is related to magnetic field strength (B) by:
Where Φ is in webers, B is in teslas, A is the area in square meters, and θ is the angle between the magnetic field and the normal to the surface.
Typical Magnetic Field Strengths
| Source/Environment | Typical Field Strength | Notes |
|---|---|---|
| Interstellar space | ~10-12 T | Extremely weak fields |
| Earth's magnetic field | 25-65 μT (0.25-0.65 G) | Varies by location and altitude |
| Refrigerator magnet | 5-10 mT (50-100 G) | Common household magnet |
| Small neodymium magnet | 0.2-0.5 T (2,000-5,000 G) | Strong permanent magnet |
| Medical MRI scanner | 1.5-7 T (15,000-70,000 G) | Diagnostic imaging |
| Research superconducting magnets | 10-20 T (100,000-200,000 G) | Scientific experiments |
| Strongest sustained lab field | ~45 T (450,000 G) | National High Magnetic Field Laboratory |
| Neutron stars | 108-1011 T | Extremely dense astronomical objects |
Magnetic Field Applications
- Medical Imaging: MRI (Magnetic Resonance Imaging) scanners use strong magnetic fields to generate detailed images of the body's internal structures.
- Electric Motors and Generators: These devices convert between electrical and mechanical energy using magnetic fields.
- Particle Accelerators: Magnetic fields are used to steer charged particles in accelerators and colliders.
- Magnetic Storage: Hard drives, magnetic tapes, and other storage media use magnetic fields to store information.
- Electromagnets: Used in various applications from industrial lifting to scientific research.
- Maglev Trains: These trains use magnetic levitation to move without touching the ground.
- Compass Navigation: Traditional compasses align with Earth's magnetic field for navigation.
Lorentz Force
The force (F) experienced by a charged particle moving through a magnetic field is given by:
Where F is in newtons, q is the charge in coulombs, v is the velocity in meters per second, B is the magnetic field strength in teslas, and θ is the angle between the velocity and magnetic field.
Magnetic Field vs. Magnetic Field Strength
In electromagnetism, two related quantities are often discussed:
- Magnetic Field Strength (H): Measured in amperes per meter (A/m), it represents how strong a magnetic field is generated by a current.
- Magnetic Flux Density (B): Measured in tesla (T), it describes the actual magnetic field that results, taking into account the medium's properties.
In a vacuum or air, these are related by: B = μ0H, where μ0 is the magnetic permeability of free space (4π × 10-7 H/m).