Solenoid Magnetic Field Calculator

Calculate the magnetic field strength inside solenoid coils

Calculate Solenoid Magnetic Field

Total number of wire turns in the coil

Current flowing through the solenoid

Length of the solenoid coil

Magnetic Field Results

0
Nanotesla (nT)
Magnetic Field Strength
0 turns/m
Turn Density
In Tesla:0 T
In Millitesla:0 mT
In Microtesla:0 μT
In Gauss:0 G
Field Strength:0 A/m

Formula: B = μ₀ × N × I / L

Calculation: B = 1.257e-6 × 0 × 0 / 0

Turn density: n = 0 turns/meter

Magnetic field strength: H = 0 A/m

Magnetic Field Analysis

Example Calculation

Electromagnetic Coil

Application: Laboratory electromagnet

Number of turns: 100 turns

Current: 0.1 A

Coil length: 10 cm = 0.1 m

Calculation

B = μ₀ × N × I / L

B = 1.25664 × 10⁻⁶ × 100 × 0.1 / 0.1

B = 1.25664 × 10⁻⁶ × 100 × 1

B = 1.257 × 10⁻⁴ T = 0.1257 mT = 1.257 G

This creates a moderate magnetic field suitable for lab demonstrations

Solenoid Magnetic Field Formula

B = μ₀ × N × I / L

Magnetic field inside solenoid

B: Magnetic field (T)
μ₀: Vacuum permeability (1.257 × 10⁻⁶ T·m/A)
N: Number of turns
I: Electric current (A)
L: Solenoid length (m)

Typical Magnetic Field Strengths

Earth's field:25-65 μT
Refrigerator magnet:5-10 mT
MRI machine:1.5-3 T
Lab electromagnet:0.1-2 T
Neodymium magnet:0.2-1.4 T

Magnetic Field Units

Tesla (T)

SI unit of magnetic field

Gauss (G)

1 T = 10,000 G

Millitesla (mT)

1 T = 1,000 mT

Microtesla (μT)

1 T = 1,000,000 μT

Solenoid Physics

Field is uniform inside, zero outside

Field strength proportional to current

More turns = stronger field

Shorter length = stronger field

Direction follows right-hand rule

Understanding Solenoid Magnetic Fields

What is a Solenoid?

A solenoid is a coil of wire wound in a helical pattern, typically around a cylindrical form. When electric current flows through the wire, it creates a magnetic field that is concentrated inside the coil and nearly zero outside.

Magnetic Field Properties

  • Uniform field inside the solenoid
  • Negligible field outside the solenoid
  • Field direction determined by current direction
  • Field strength proportional to current and turn density

Mathematical Derivation

B = μ₀ × n × I

Where n = N/L (turn density)

Key Physics Principles

Ampère's Law: ∮B⋅dl = μ₀I_enclosed
Biot-Savart Law: dB = (μ₀/4π) × (I dl × r̂)/r²
Right-hand Rule: Thumb = current, fingers = field
Superposition: Total field = sum of individual contributions

Note: This formula assumes an ideal, infinitely long solenoid. Real solenoids have edge effects that slightly reduce the field strength.

Applications & Use Cases

Medical Devices

MRI machines, magnetic therapy devices, medical pumps

Industrial

Lifting magnets, magnetic separators, actuators

Scientific Research

Particle accelerators, laboratory electromagnets, NMR spectrometers

Design Considerations

Field Optimization

  • • Increase current for stronger field
  • • Use more turns per unit length
  • • Reduce solenoid length (increase turn density)
  • • Add ferromagnetic core (multiply by μᵣ)
  • • Minimize air gaps in magnetic circuit

Safety & Practical Limits

  • • Power dissipation limits current
  • • Cooling required for high-power operation
  • • Magnetic saturation in core materials
  • • Safety concerns with strong fields (>0.1 T)
  • • Electromagnetic interference considerations