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What was early capacitor used for? 开始学习
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The early capacitor (Leyden jar) was used to store static electric charge for experiments.
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开始学习
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A capacitor is a passive electronic component that stores electrical energy in an electric field.
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What does capacitor consist of? 开始学习
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It consists of two conductive plates separated by an insulating material called a dielectric.
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What happens when you connect your capacitor to the power supply? 开始学习
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When connected to a DC power supply, current flows momentarily, charging the capacitor until the voltage across it equals the supply voltage, at which point current stops.
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What is the key property of a capacitor? 开始学习
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Its key property is capacitance, which is its ability to store electrical charge.
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How can capacitance be denoted? 开始学习
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It is denoted by the letter 'C'.
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What is the unit of measurement for capacitance? 开始学习
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What factors does capacitance depend on? 开始学习
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It depends on the surface area of the plates (A), the distance between them (d), and the dielectric constant (ε) of the insulating material. (C = εA/d)
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What affects the behaviour of capacitors in a circuit? 开始学习
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The frequency of the applied voltage (AC vs. DC) and the circuit configuration.
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How do capacitors behave in DC circuits? 开始学习
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They act as an open circuit (infinite resistance) once fully charged, blocking DC current.
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How do capacitors behave in AC circuits? 开始学习
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They allow AC current to pass, but offer a frequency-dependent opposition called capacitive reactance.
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How does relative permittivity affect capacitance? 开始学习
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A higher relative permittivity (dielectric constant) of the insulating material increases the capacitance.
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Can you give the formula for calculating the energy stored in a capacitor? 开始学习
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The energy (E) is equal to one-half times the capacitance (C) times the voltage (V) squared.
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What 3 effects of a capacitor in a circuit are mentioned in the video? 开始学习
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Coupling, Decoupling, Filtering, and Energy Storage.
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How can capacitors protect sensitive electronic components? 开始学习
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As decoupling capacitors, they smooth out voltage spikes and provide a local reservoir of charge.
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How can capacitors be used as filters? 开始学习
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They can block low-frequency signals (DC) while passing high-frequency signals (AC), or be used in combination with resistors/inductors to create specific frequency response circuits.
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What types of capacitors are mentioned in the video? Where are they used? 开始学习
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Common types include ceramic (high-frequency circuits), electrolytic (power supply filtering, high capacitance), and film (precision applications).
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