Key relationship
L=µ₀µrN²A/ℓ; M=k√(L₁L₂); ε₂=−M dI₁/dt.
Physics · Class 12
Self and mutual inductance
Inductance measures flux linkage per ampere. More turns increase self-inductance quadratically. Mutual inductance also depends on how well the two coils share flux.
Open the interactive experiment →Self and mutual inductance
தன்தூண்டல் N²-க்கு நேர்விகிதம். இரண்டு சுருள்கள் பகிரும் பாயம் பரஸ்பரத் தூண்டலை நிர்ணயிக்கும்.
Key notes, relationships and model limits
Remember
Inductance measures flux linkage per ampere. More turns increase self-inductance quadratically. Mutual inductance also depends on how well the two coils share flux.
Common trap
An inductor opposes current change, not steady current. Mutual induction also depends on how strongly the coils are coupled.
Model limits
Long linear solenoids sharing geometry, constant permeability, no saturation or winding resistance.
What you will learn
Use the controls and plotted relation to explain self and mutual inductance.
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
For N=500, A=10 cm², ℓ=0.2 m and air core, L≈1.571 mH.
Why this matters
The model connects self and mutual inductance 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 of an unchanged solenoid makes L?
- Twice as large.
- Four times larger.
- Half as large.
Read the explanation
Four times larger.
Course connection: Class XII Chapter 6. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.