3 Basic Circuit Components Free Online FlashCards

What does a circuit source do?

A source provides electrical energy by maintaining a voltage or supplying a current.

How do DC and AC sources differ?

A DC source has fixed positive and negative terminal polarities. An AC source periodically reverses its voltage and current direction.

What must be present for a source to drive current?

Current requires a complete conducting path between the source’s terminals; a source alone does not guarantee current flow.

What relationship does Ohm’s law give for a resistor?

For an ohmic resistor, voltage, current, and resistance are related by Ohm’s law: $V = IR$.

Why must a resistor have an appropriate power rating?

A resistor limits current and commonly converts electrical energy into heat. Its power rating must be adequate to prevent overheating.

How do open and closed switches affect a circuit path?

An open switch breaks the path, so ideally no current flows through it. A closed switch completes the path and acts approximately like a wire.

How does an incandescent lamp produce light?

An incandescent lamp produces light by heating a filament until it glows. The filament behaves roughly like a resistor, though its resistance changes as it heats.

What does an LED need for safe circuit operation?

An LED needs the correct polarity and operation within its current rating. It commonly uses a series resistor or another current-limiting circuit.

How are a capacitor’s charge, capacitance, and voltage related?

Capacitance relates a capacitor’s stored charge to its voltage: $Q = CV$.

How does an ideal capacitor behave during and after DC charging?

An ideal capacitor’s voltage cannot change instantaneously. In a simple DC circuit, it carries current while charging or discharging, but no steady current after reaching a steady voltage.

What does an inductor store, and what change does it oppose?

An inductor stores energy in a magnetic field when current flows and opposes changes in current.

How does an ideal inductor behave in settled DC conditions?

In an ideal DC circuit, once conditions have settled, an inductor behaves like a wire.