I'm a Arduino and Electronics newbie. I've been trying to learn a bit more from AC/DC power to circuits and everything that I need to know to make cool projects. I have some very basic resistors questions:
- In this image http://itp.nyu.edu/physcomp/uploads/dcmotor_bb2.png, why is the resistor in that place and not connected to a LED or something instead of the ground?
- When I'm designing a circuit do I have always to make all the math to be sure that there is resistance in the circuit? And from the + to the - how much resistance should there be?
- When the Arduino is connected to a LED it needs a resistor, why doesn't it need a resistor when it connects to a chip?