Key relationship
L=μ₀μrN²A/ℓ; U=½LI²; emf=−L dI/dt.
Physics · Practical apparatus
Coil inductance geometry
Vary one geometric factor at a time. Turns enter quadratically; area and permeability linearly; length inversely. The negative induced emf expresses opposition to an increasing current.
Open the interactive experiment →Coil inductance geometry
திருப்புகள் வர்க்கமாகவும் பரப்பும் ஊடுருவுத்திறனும் நேராகவும் தூண்டலை மாற்றும். அதிக நீளம் தூண்டலைக் குறைக்கும்.
Key notes, relationships and model limits
Practical tip
Vary one geometric factor at a time. Turns enter quadratically; area and permeability linearly; length inversely. The negative induced emf expresses opposition to an increasing current.
Common trap
A fixed μr cannot describe saturation at arbitrary current.
Model limits
Long ideal solenoid; uniform core with fixed linear permeability. Fringing, resistance and ferromagnetic saturation omitted. Drawing turns are symbolic.
What you will learn
Investigate inductance factors and emf sign.
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
N200,A5 cm²,ℓ10 cm,μr1 gives about0.2513 mH.
Why this matters
The model connects coil inductance geometry with an observable reading. Check the equation and assumptions before applying it.
Before you start
SI units · algebra · graph reading
Check your understanding
Doubling turns with all else fixed changes L to?
- Twice
- Four times
- Half
Read the explanation
L contains N².
Course connection: Virtual apparatus preparation. Check exact board/exam membership in the syllabus sources. Physical practical work remains necessary.