Read LCR Circuits: Resonance, Phase and Impedance
An LCR circuit becomes simple only after you compare inductive and capacitive reactance. Resonance is the point where their difference vanishes.
Electricity questions depend on identifying charge, a conducting path and the condition that controls current or magnetic effect.
Start with the condition
Keep peak and rms quantities separate.
Build the governing relation
Away from resonance, the sign of X_L - X_C tells whether the circuit is inductive or capacitive.
Finish with a physical check
Check the limiting case before selecting an option: remove the special feature in the diagram or make the relevant parameter very large or very small. The result should reduce to a familiar relation.
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- ✓State the physical condition before choosing a formula.
- ✓Keep direction, sign and constraint information explicit.
- ✓Test one limiting case before committing to an option.
Do not equate equal currents in two switched circuits with resonance until you write the impedance for each configuration.
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