Why do capacitors dis/charge suddenly and then slow down?

Capacitors are made up of two plates (& so the symbol) which you can imagine as 'boxes' of opposite polarity and are seperated with insulation. 

As capacitors charge, the negative box keeps filling with electrons while the other (positive) box loses any electrons still in them due to repulsion from this negative box. Since the negative box is relatively empty to start with, electrons fill in very quickly. As their numbers increase, the capacity of the box reduces and the electrons repel any new electrons coming in, which slows the flow of electrons. 

Similarly for capacitor discharging, the now filled negative box easily looses its electrons to the empty positive box very quickly. But as their numbers start to even out, the flow slows down. Hence, the graphs potray an exponential relationship for capacitors when charging and discharging takes place. 

This is quite similar to you filling/emptying a balloon with water; it starts to fill/empty very suddenly at the beginning but slows down over a period of time. .

SB
Answered by Shail B. Physics tutor

19289 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

(ii) Describe and explain how the horizontal component of the water jet varies from point X to point Y. (2 marks)


Assuming the Earth is a perfect sphere of radius R. By how much would your mass (m), as given by a scale, change if you measured it on the north pole and on the equator?


A person swims from a depth of 0.50 m to a depth of 1.70 m below the surface of the sea. density of the sea water = 1030 kg/m^3 gravitational field strength = 9.8 N/kg Calculate the increase in pressure on the swimmer. Give the Unit.


Using Newton's law of universal gravitation, show that T^2 is proportional to r^3 (where T is the orbital period of a planet around a star, and r is the distance between them).


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences