Key relationship
Baxis=µ₀NIa²/[2(a²+x²)³ᐟ²].
Physics · Class 12
Biot–Savart circular coil
Biot–Savart contributions from a circular coil add along its axis. Centre field grows with current and turn count and decreases with coil radius.
Open the interactive experiment →Biot–Savart circular coil
வட்டக் கம்பிச் சுருளின் அச்சுப் புலத்தில் குறுக்குக் கூறுகள் ரத்தாகும். மையப் புலம் NI-க்கு நேர்விகிதம்.
Key notes, relationships and model limits
Remember
Biot–Savart contributions from a circular coil add along its axis. Centre field grows with current and turn count and decreases with coil radius.
Common trap
The coil’s axial field is largest at its centre and decreases along the axis; it is not uniform everywhere.
Model limits
Thin circular coil in vacuum. The graph always shows the coil axial profile; field-source selection lets you compare analytic source readings.
What you will learn
Use the controls and plotted relation to explain biot–savart circular coil.
Try the experiment
Try both scenarios, change one control, and predict the result before checking the graph and readouts.
Think of it this way
Change one input while keeping the others fixed, as you would in a controlled experiment.
Worked example
A 100-turn coil of radius 0.1 m at 2 A has centre B≈1.257 mT.
Why this matters
The model connects biot–savart circular coil with an observable reading. Check the equation and assumptions before applying it.
Before you start
SI units · algebra · graph reading
Check your understanding
Doubling coil turns at fixed geometry and current gives centre field?
- Four times the original field.
- Twice the original field.
- Half the original field.
Read the explanation
Twice the original field.
Course connection: Class XII Chapter 4. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.