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Physics · Class 12

LCR response to DC and AC

Alternating Current

Compare AC steady-state frequency response with switched DC subcircuits. The DC selector explicitly chooses RC, LR or ideal LC; it is not a full damped second-order LCR transient solver.

Open the interactive experiment →

LCR response to DC and AC

AC-இல் மறுமின்தடை அதிர்வெண்ணைச் சாரும். நிலையான DC-இல் தேக்கி மின்னோட்டத்தைத் தடுக்கும்; இலட்சிய சுருள் குறுக்கிணைப்பாகும்.

Key notes, relationships and model limits

Key relationship

AC: Z=√(R²+(ωL−1/ωC)²). DC: C blocks steady current; L becomes a short ideally.

Remember

Compare AC steady-state frequency response with switched DC subcircuits. The DC selector explicitly chooses RC, LR or ideal LC; it is not a full damped second-order LCR transient solver.

Common trap

The AC panel is a full series-LCR steady-state model. The DC selector studies RC, LR or ideal LC, rather than a damped full-LCR switch-on.

Model limits

AC is a full series LCR steady state. DC study is explicitly scoped to selectable RC, LR and ideal LC subcircuits with stated initial conditions.

What you will learn

Use the controls and plotted relation to explain lcr response to dc and ac.

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 Ω and 100 µF RC circuit has 0.01 s time constant; its current decays to zero under DC.

Why this matters

The model connects lcr response to dc and ac with an observable reading. Check the equation and assumptions before applying it.

Before you start

SI units · algebra · graph reading

Check your understanding

An ideal capacitor in steady DC behaves as?

Read the explanation

An open circuit after charging.

Course connection: Class XII Chapter 7. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.