Role of resistance?

What if we charge a capacitor without resistance. What will happen? My teacher taught me that without the presence of external resistance capactors charge and discharge instantly.

randofo6 months ago

Not quite instantly, but yes. That is more or less accurate.

A resistor serves to slow down the charge rate of the capacitor.

What you are talking about is an RC timing circuit. Here is a description, which is a bit confusing about how they work:

http://www.electronics-tutorials.ws/rc/rc_1.html

If you understand microcontrollers, you can take a look at the "RCtime" example. In this circuit the Arduino counts the amount of time it takes a capacitor to charge through a resistor. So, if you increase resistance, the amount of time increases (and a decrease would decrease the time). This is a little easier to wrap ones head around (assuming you understand Arduino at all).

https://www.arduino.cc/en/Tutorial/RCtime