Question T6A04
From subelement T6 - T6A
What electrical component stores energy in an electric field?
Why is this correct?
A capacitor stores energy in an electric field created between its conductive plates separated by an insulator (dielectric). When voltage is applied, opposite charges accumulate on each plate, creating the electric field that holds the energy. Inductors store energy in magnetic fields around coiled wire, varistors are voltage-dependent resistors, and diodes control current direction—none store energy in electric fields.
Memory tip
Remember the structural clue: capacitors have separated plates creating space for an electric field, while inductors are coils creating magnetic fields. The physical construction directly relates to the type of energy storage—plates mean electric field storage.
Learn more
In practical circuits, capacitors smooth power supply ripple by storing energy during voltage peaks and releasing it during dips. They also block DC while passing AC signals, making them essential for coupling stages in transmitters and receivers. The capacitor's ability to store charge at specific voltages enables precise frequency tuning when paired with inductors in resonant circuits, fundamental to amateur radio operation.
Think about it
Why do you think capacitors are often paired with inductors in radio circuits if they store energy in opposite types of fields?