Diode Drop
Strangely, the voltage difference across a diode is nearly constant, at about 0.6 Volts. This means that a diode is another component that pays no attention to Ohm's law.
There are some applications where it's handy to have a .6V value, but mostly it's just important to remember that the diode drop is there in your circuit.
Quick Challenge: Set up each of the circuits below. Use 1N914 diodes, or similar. Measure the indicated voltage levels with a VOM -- what do you expect to read?
