Jump to content
Electronics-Lab.com Community

Paralell resistors

Recommended Posts

    I recently found out that if you have resistors of the same value wired in paralell, the resistance is lower than one of the resistors in the paralell. For example, if you have 2 resistors that are 50 ohms each, wire them in paralell and their resistance is 25 ohms each. I don't understand how having resistors in paralell will lower resistance. Can someone tell me why the resistance divides by 2 when you add 2 resistors of the same value?

Thanks a ton.

Link to comment
Share on other sites

Any number of resistors of the same value in parallel is equal to the resistor value divided by the number of resistors, it's not just limited too 2... i.e. 10, 100ohm resisistors in parallel is 100/10=10ohms... it's one of those things that works out that way given certain conditions.

The equation for any values in parallel is Rval= 1/ (1/R1+1/R2...1/Rn). I suppose you could algebraically manipulate the equation to get Rval=R1/n when R1=R2=R3... if you wanted to really prove it to yourself.

Link to comment
Share on other sites

I believe you are confused because you stated that two 50 Ohm resistors in parallel causes them to become 25 Ohms each. This is incorrect. They stay 50 Ohms each, but the resistance of the whole becomes 25 Ohms.

A single water pipe has a certain resistance to flow, but two such pipes permit twice as much flow. The same principle applies with electrical resistance. Two identical parallel paths provide half the total resistance that one would provide.

Bugger. Sorry Zeppelin.

Link to comment
Share on other sites

  • 3 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...