Practical takeaway
Capacitors store energy in an electric field, inductors in a magnetic field, impedance is opposition to AC current, and electrical power is voltage times current.
T5C · Components, impedance and power
Capacitance, Inductance, Impedance & Power
Four relationships and a few units cover this Technician group.
Technician exam focus
Know the names and units, the proper kHz/MHz abbreviations, what impedance means, and three straightforward DC power calculations.
1. Capacitance and inductance
CapacitanceStores energy in an electric fieldfarad (F)
InductanceStores energy in a magnetic fieldhenry (H)
A capacitor uses conductive surfaces separated by an insulator. An inductor is commonly a coil of wire. For Technician T5C, the important pairing is electric field → capacitance → farad and magnetic field → inductance → henry.
2. Impedance
Impedance is opposition to AC current flow. Its unit is the ohm (Ω), the same unit used for resistance. For the Technician exam, that definition is enough; the deeper reactance details can wait until you want them.
3. RF units
kHz is kilohertz and MHz is megahertz. The letter case matters: lowercase k for kilo, uppercase M for mega, and Hz for hertz.
4. DC power
When division is needed, P stays on top: E = P ÷ I and I = P ÷ E.
See it in SPARKA
T5C checklist
- Capacitance → electric field → farad.
- Inductance → magnetic field → henry.
- Impedance → opposition to AC current → ohms.
- Correct symbols: kHz and MHz.
- P = E × I; if dividing, P is the numerator.