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What is the difference between resistance and reactance? What are 2 kinds of reactance? 开始学习
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Resistance opposes both AC and DC and dissipates energy as heat. Reactance opposes only AC and stores and releases energy. The two kinds are Inductive Reactance (X_L) and Capacitive Reactance (X_C).
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开始学习
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Impedance (Z) is the total opposition a circuit offers to alternating current. It is a complex quantity combining both resistance (R) and reactance (X).
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What are three ways current can change in a circuit? 开始学习
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It can change in magnitude (amplitude), frequency, and phase.
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What does Inductive reactance cause? 开始学习
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It causes the current to lag behind the voltage.
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What does capacitive reactance cause? 开始学习
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It causes the current to lead the voltage.
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Where is reactance observed: AC circuits or DC circuits? 开始学习
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Reactance is observed only in AC circuits. In a steady DC circuit, inductors act as short circuits and capacitors as open circuits.
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How does resistance affect the current? 开始学习
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Resistance limits the amount of current that flows for a given voltage.
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Give the definitions of an electrical and an electronic circuit. 开始学习
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An electrical circuit is a path for transmitting electric current, often for power distribution and conversion. An electronic circuit uses components to control the flow of electrons for processing information.
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What circuit elements are called active? What circuit elements are called passive? 开始学习
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Active elements can inject power into a circuit (e.g., transistors, ICs). Passive elements cannot and can only absorb or store energy (e.g., resistors, capacitors, inductors).
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Give the examples of active and passive elements. 开始学习
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Active: Transistors, operational amplifiers, batteries. Passive: Resistors, capacitors, inductors, diodes.
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What types of circuits can you name? 开始学习
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Series circuits, parallel circuits, and series-parallel (combination) circuits.
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What is the difference between series and parallel circuits? 开始学习
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In a series circuit, components are connected end-to-end, so the same current flows through all of them. In a parallel circuit, components are connected across common points, so the same voltage is applied to all of them.
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What are the main troubles in circuits? 开始学习
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Open circuits (break in the path), short circuits (unintended low-resistance path), and component failure.
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