THE ENERGY STORED IN CAPACITOR

1. Definition
   A capacitor is a device used for storing energy. When we connect a battery across the two plates of a capacitor, it gets charged. The potential difference gradually increases across the two plates and the battery had to do more work to deliver the same amount of charge due to the continuous increase in potential difference.

2. Formula and Example


Where:
  • W stands for work (J)
  • C stands for capacitance (F)
  • Q/q stands for charge (C)
  • V stands for electric potential (Volt)

Example:
   An air-filled parallel plate capacitor has a capacitance of 5.0 pF. A potential of 100 V is applied across the plates, which are 1.0 cm apart, using a storage battery. What is the energy stored in the capacitor?
Answer:


3. Important Figure

    Pieter Van Musschenbroek was a Dutch physicist who invented the Leyden jar, a device used for storing electrical charges. Musschenbroek was a professor of mathematics and physics at the University of Leyden in Holland. Musschenbroek was conducting an experiment in which he poured water into a glass jar and connected the jar by wire to a friction machine that produced static electricity. The device, which was later named the Leyden jar, is stated to be the prototype of capacitors.  

4. Uses in Daily Life
   In some cases, like the flash circuit of a camera, you need a buildup of energy and then a sudden release. This is exactly what a capacitor does. In the camera circuit, you press the button to take the picture and a charge is released to the capacitor. Once it has reached the peak level, the capacitor discharges, causing a flash.

Picture sources:
https://capsun.en.made-in-china.com/product/FXJxRrHCZDks/China-Factory-Direct-Sales-125V22000UF-Super-Large-Capacity-Capacitor-Energy-Storage-Aluminum-Electrolytic-Capacitor-Spot-Welder-Electrolytic-Capacitor-Capacitor.html

http://www.calctool.org/MOBILECALC/eng/electronics/capacitor_energy

http://farside.ph.utexas.edu/teaching/302l/lectures/node52.html

https://en.wikipedia.org/wiki/Pieter_van_Musschenbroek

https://sciencing.com/list-uses-capacitors-8059446.html








   


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