Biot-Savart Law Calculator

Enter your Point Charge (Q), Velocity (v), Angle (θ), and Distance (r) into the Biot-Savart Law Calculator to find the Magnetic Field (B) produced by a moving charge — with results shown in standard and scientific notation, plus the Permeability of Vacuum (μ₀) used in the calculation.

C

Electric charge in Coulombs

m/s

Velocity of the charge in meters per second

°

Angle between velocity and position vector in degrees

m

Distance from the charge to observation point in meters

Results

Magnetic Field (B)

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Magnetic Field (Scientific)

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Permeability of Vacuum (μ₀)

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Magnetic Field Components

Frequently Asked Questions

What is the Biot-Savart law?

The Biot-Savart law describes the magnetic field generated by a steady electric current. It states that the magnetic field B at any point is proportional to the current, the length of the current element, and inversely proportional to the square of the distance from the current element.

How do I calculate magnetic field using the Biot-Savart law?

The magnetic field is calculated using the formula B = (μ₀/4π) × (Q × v × sin(θ))/r². Where μ₀ is the permeability of vacuum, Q is the point charge, v is velocity, θ is the angle between velocity and position vector, and r is the distance.

What is the permeability of vacuum (μ₀)?

The permeability of vacuum (μ₀) is a fundamental physical constant equal to 4π × 10⁻⁷ H/m (henries per meter) or N/A² (newtons per ampere squared). It relates the magnetic field to the current that produces it.

Why is the angle important in Biot-Savart calculations?

The angle θ between the velocity vector and the position vector is crucial because it determines the sine component in the cross product. When θ = 90°, the magnetic field is maximum. When θ = 0° or 180°, the magnetic field is zero.

What units are used for magnetic field strength?

Magnetic field strength is measured in Tesla (T) in the SI system. One Tesla is equal to one weber per square meter (Wb/m²) or one newton per ampere-meter (N/(A·m)).

How does distance affect the magnetic field?

The magnetic field strength is inversely proportional to the square of the distance (1/r²). This means that doubling the distance reduces the magnetic field to one-fourth of its original value.

Can this calculator be used for multiple current elements?

This calculator computes the magnetic field for a single current element or point charge. For multiple elements, you would need to calculate each contribution separately and then use vector addition to find the total field.

What is the difference between Biot-Savart law and Ampère's law?

The Biot-Savart law can calculate magnetic fields for any current configuration, while Ampère's law is easier to use but only works for highly symmetric current distributions like infinite straight wires or circular loops.

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