MCQ Detailed View

In an electronic circuit, a capacitor (capacitance) is commonly used to block direct current (DC) while allowing alternating current (AC) to pass. This property of capacitors makes them essential components in signal processing, coupling, and filtering applications.

A capacitor stores electrical energy in the form of an electric field between its plates. When DC voltage is applied, the capacitor charges up to the applied voltage, and once fully charged, it prevents further DC current from flowing through the circuit. However, AC voltage causes the capacitor to continually charge and discharge, allowing AC signals to pass, which is why capacitors are widely used in AC coupling and filtering circuits.

Other circuit elements behave differently:

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  Resistors oppose current flow but cannot completely block DC.

  
  


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  Inductors resist changes in current and can block AC at high frequencies but allow DC to pass.

  
  


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  Diodes allow current to flow in one direction but do not generally block DC unless configured in a specific circuit.

  
  

Capacitors are also used in tuning circuits, timing applications, and power supply filters. In electronics, understanding how different components interact with AC and DC is crucial. The ability of a capacitor to block DC while passing AC is a foundational concept in circuit design, electronics, and physics.

This question belongs to Physics, specifically the study of electromagnetism and electronics. Knowing the behavior of capacitors in AC and DC circuits is essential for students to understand practical applications in signal processing, electronic devices, and communication systems.