I came across a pile of electronics parts that were thrown out and am going through them and sorting them out. I have what I believe is a resistor. It is rust colored and marked 100R and +/-5%. I'm sure someone can help identify them and where would they have been used. Sorry, I'm a newbie, guilty!

 

No problem, everyone is/was a newbie at some point, bwilliams!!

That would appear to be a 100 ohm resistor, with a +/- 5% tolerance. So it's 95 to 105 ohms...

They often put an "R" after resistors whose values are less than 1,000 ohms, after which they get a "K" suffix. Ex: 47,000 ohms = 47k. The "R" helps you know what range it's in, and sort of provides an identifier that it is a resistor.


Can you post a pic? Sounds like a power resistor, if it's big enough for writing rather than colored bands. And, any other unidentified things can be put in a photo for here, as well.

 

100R suggests that the resistance is 100 ohms. This can be easily verified using an ohmmeter.