impedance

/ɪmˈpiːdns/ (bre, ipa) · /ɪmˈpiːdns/ (ame, ipa) · /im-ˈpē-dᵊn(t)s/ (ame, mw)

impedance — noun

1. the combined force that slows or blocks the flow of electricity in a circuit tha

1.名詞C2
釋義

the combined force that slows or blocks the flow of electricity in a circuit that carries changing current (alternating current). It includes the effects of resistance, capacitance, and inductance, and is measured in a unit called the ohm.

例句

Élise measured the impedance of the new speakers to see if they matched the amplifier.

measure + impedance + of [component]

The cable had a high impedance, so the signal grew weak before reaching Daichi's recorder.

high impedance causes signal loss

同義詞
  • resistance

    Related but distinct — resistance applies to DC circuits and is only one part of impedance; impedance includes both resistance and reactance for AC circuits.

  • reactance

    The component of impedance that comes from capacitance and inductance, not from pure resistance.

反義詞
  • conductance

    The measure of how easily electricity flows through a circuit — the opposite of impedance.

文法句型

the impedance of [device/circuit]

[adjective] impedance

impedance + verb

用法筆記

Impedance is the AC (alternating current) equivalent of resistance in DC (direct current) circuits. The symbol is Z, and the unit is the ohm (Ω). Commonly used in speaker specifications, audio equipment, and circuit design. Input impedance and output impedance are two frequently encountered types.

常見錯誤

The impedance of this DC battery is five ohms.
The resistance of this DC battery is five ohms.
💡Impedance is a term for alternating current (AC); for direct current (DC), the correct term is resistance.
This wire has zero impedance.
This wire has very low impedance.
💡All real circuits have some impedance; zero impedance only exists in theoretical ideal models.