Plotly Graph
The graph updates from the selected method and current values.
Calculator Form
Use the selector first. Then enter values in the visible fields.
Example Data Table
| Method | Sample Inputs | Calculated B Field |
|---|---|---|
| Straight Wire | I = 15 A, r = 0.03 m, μr = 1 | 0.0001 T, 100 µT, 1 G |
| Circular Loop | I = 6 A, N = 20, R = 0.08 m, μr = 1 | 0.00094248 T, 0.94248 mT, 9.42478 G |
| Solenoid | I = 2.5 A, N = 800, L = 0.40 m, μr = 1 | 0.00628319 T, 6.28319 mT, 62.83185 G |
| Force Relation | F = 0.018 N, q = 3e-6 C, v = 2500 m/s, θ = 90° | 2.4 T, 2400 mT, 24000 G |
Formula Used
1. Straight wire: Use B = (μ₀ × μr × I) / (2πr). This finds field strength around one long conductor.
2. Circular loop: Use B = (μ₀ × μr × N × I) / (2R). This estimates the center field of a loop.
3. Solenoid: Use B = μ₀ × μr × (N / L) × I. This suits a tightly wound coil.
4. Force relation: Use B = F / (q × v × sinθ). This derives field strength from motion and force.
Unit note: μ₀ equals 4π × 10-7 T·m/A. The page also converts Tesla into milliTesla, microTesla, and Gauss.
How to Use This Calculator
- Select the method that matches your problem.
- Enter the required values in the visible fields.
- Click Calculate B Field to compute the result.
- Read the result card above the form.
- Check the formula, substitutions, and converted units.
- Review the Plotly graph for trend analysis.
- Use the history section for repeated comparisons.
- Download the stored results as CSV or PDF.
Calculation History
The table stores recent results from this session.
No saved calculations yet. Submit the form to build history.
FAQs
1. What does B field mean here?
It means magnetic flux density. The calculator expresses it in Tesla first. It also converts the same result into milliTesla, microTesla, and Gauss.
2. Which method should I choose?
Choose straight wire for one conductor, circular loop for center field, solenoid for coil field, and force relation when force, charge, speed, and angle are known.
3. Why does the force method need angle?
The magnetic force depends on sinθ. When angle changes, the perpendicular motion changes too. A zero-degree or one-hundred-eighty-degree angle makes the sine zero, so the formula fails.
4. Can I use relative permeability above one?
Yes. Relative permeability changes the field in materials. Air is usually close to one. Ferromagnetic cores can be much higher, depending on the chosen material.
5. Why are my values extremely small?
Magnetic field values often become tiny when current is low or distance is large. Check unit sizes carefully. The converted units help you read very small answers more comfortably.
6. Is the loop formula valid everywhere?
No. The implemented loop formula calculates field strength at the loop center. Off-center field problems need a different relation and more advanced geometry.
7. What does the Plotly graph show?
The graph shows how B changes when one key variable varies. It helps you inspect trends quickly and compare sensitivity for the selected method.
8. Does the export include all results?
Yes. CSV export includes the saved session history. PDF export packages the same history into a simple report you can share or archive.