Electromagnetic Oscillations and Currents

These flashcards cover key vocabulary and concepts related to electromagnetic oscillations and currents, emphasizing LC circuits, energy storage, oscillation behavior, and circuit components.

LC Circuit

A circuit that contains both an inductor (L) and a capacitor (C) that oscillates electromagnetic energy.

Electromagnetic Oscillation

The variation of voltage and current in LC circuits that occurs sinusoidally with time.

Inductor

A component that stores energy in a magnetic field and opposes changes in current.

Capacitor

A component that stores energy in an electric field and stores charge.

Charge (q)

The amount of electrical energy stored in a capacitor, given by the equation q = CΔV.

Damped Oscillation

An oscillation in an RLC circuit where energy is lost to resistance, causing the amplitude to decrease over time.

Resonance

A condition in an RLC circuit where the inductive reactance and capacitive reactance are equal, resulting in a maximum current.

Impedance (Z)

The total opposition to current flow in an AC circuit, including resistance, inductive reactance, and capacitive reactance.

Root-Mean-Square (RMS) Current

The effective value of alternating current that represents the direct current value producing the same power.

Power Factor

The ratio of real power used in a circuit to the apparent power flowing in the circuit, related to the phase difference.

Transformers

Devices that step up or step down AC voltages using coils of wire and induction.

Rectifier

A device that converts alternating current (AC) to direct current (DC), typically using diodes.

Voltage Drop

The decrease in voltage across a circuit element, such as a resistor or inductor.

LC Circuit

A circuit that contains both an inductor (L) and a capacitor (C) that oscillates electromagnetic energy, with an angular oscillation frequency given by \omega0 = 1 / \sqrt{LC} . Alternatively, the frequency is f0 = 1 / (2\pi\sqrt{LC}) .

Electromagnetic Oscillation

The variation of voltage and current in LC circuits that occurs sinusoidally with time, often described by a sinusoidal function with a frequency determined by the circuit components.

Inductor

A component that stores energy in a magnetic field and opposes changes in current. Its inductive reactance is given by X_L = \omega L = 2\pi fL .

Capacitor

A component that stores energy in an electric field and stores charge. Its capacitive reactance is given by X_C = 1 / (\omega C) = 1 / (2\pi fC) .

Charge (q)

The amount of electrical energy stored in a capacitor, given by the equation q = C\Delta V , where C is capacitance and \Delta V is the voltage difference.

Damped Oscillation

An oscillation in an RLC circuit where energy is lost to resistance, causing the amplitude to decrease over time.

Resonance

A condition in an RLC circuit where the inductive reactance and capacitive reactance are equal ( X_L = X_C ), resulting in a maximum current. The resonance frequency is f_0 = 1 / (2\pi\sqrt{LC}) .

Impedance (Z)

The total opposition to current flow in an AC circuit, including resistance (R), inductive reactance (X_L), and capacitive reactance (X_C). For a series RLC circuit, it is given by Z = \sqrt{R^2 + (X_L - X_C)^2} .

Root-Mean-Square (RMS) Current

The effective value of alternating current that represents the direct current value producing the same power. For a sinusoidal current, I_{RMS} = I_{peak} / \sqrt{2} .

Power Factor

The ratio of real power used in a circuit to the apparent power flowing in the circuit, related to the phase difference ( \phi ) between voltage and current by PF = \cos(\phi) .

Transformers

Devices that step up or step down AC voltages using coils of wire and induction. The voltage transformation ratio is given by V_s / V_p = N_s / N_p , where V_s and V_p are secondary and primary voltages, and N_s and N_p are the number of turns.

Rectifier

A device that converts alternating current (AC) to direct current (DC), typically using diodes.

Voltage Drop

The decrease in