13e_resistors - 13e: Resistors There is always some...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
13e: Resistors There is always some resistance in every circuit. A circuit is always made up of some wire, so there will be some resistance there. Even the battery has parts that offer resistance to the flow of electrons. The only circuits that come near to zero resistance are superconductors. This resistance that is from the parts of the circuit itself (especially the battery) is called internal resistance . This internal resistance is usually drawn into a circuit diagram ( schematic ) as shown in Figure 1. Notice the squiggly line just before the positive terminal of the battery? That’s to show the internal resistance of the circuit. That symbol, drawn any other place in the circuit, represents an actual resistor placed in the circuit. A resistor is a device found in circuits that has a certain amount of resistance. Why would you ever want to add resistance to a circuit by using a resistor? The most common reason is that we need to be able to adjust the current flowing through a particular part of the circuit. If voltage is constant, then we can change the resistor to change the current. I = V R If “V” is constant and we change “R”, “I” will be different. Actual Resistors The resistors that you would most likely see if you opened up a CD player, VCR, or other electronic device would look like the ones in Figure 2.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/02/2011 for the course PHYSICS 235 taught by Professor Staff during the Fall '08 term at Rutgers.

Page1 / 3

13e_resistors - 13e: Resistors There is always some...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online