Physics Keypoints: Capacitors; This study material is suitable for students sitting for the following exams: JAMB, WAEC, NECO, GCE, IJMB, and JUPEB. Capacitors are fundamental electronic components used for storing and regulating electrical energy.

They come in various types and have diverse applications, from smoothing out power supplies to timing circuits and energy storage.

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In this article, we’ll explore the types, functions, and principles of capacitors, as well as their application in parallel plate capacitors, capacitance, factors affecting capacitance, and energy storage.

(i) Types and Functions of Capacitors

Capacitors are devices that store electrical energy in an electric field. They are classified into various types, each designed for specific functions:

• Electrolytic Capacitors: These capacitors have a high capacitance and are polarized, meaning they have a positive and negative terminal. They are often used for power supply filtering and coupling in audio circuits.
• Ceramic Capacitors: Ceramic capacitors are compact and offer a range of capacitances. They are commonly used in high-frequency applications and decoupling.
• Film Capacitors: Film capacitors come in different materials, including polyester, polypropylene, and mylar. They are suitable for a wide range of applications, such as motor starting, lighting, and snubber circuits.
• Tantalum Capacitors: Tantalum capacitors are stable and can have a high capacitance for their size. They are used in devices like smartphones and laptops.
• Supercapacitors: These capacitors have an extremely high capacitance and are used for short-term energy storage, such as in regenerative braking systems in vehicles.

(ii) Parallel Plate Capacitors

A parallel plate capacitor is one of the simplest forms of capacitors. It consists of two parallel conductive plates separated by a dielectric material (an insulator). When a voltage is applied across the plates, opposite charges accumulate on the plates, creating an electric field between them.

(iii) Capacitance of a Capacitor

(iv) Relationship Between Capacitance, Plate Area, Separation, and Dielectric

(v) Capacitors in Series and Parallel

(vi) Energy Stored in a Capacitor

In conclusion, capacitors play a crucial role in electronics and electrical engineering. They come in various types, each designed for specific applications. Understanding their principles, including capacitance and the factors affecting it, as well as their energy storage capabilities, is essential for designing and troubleshooting electronic circuits.