Here are two different example circuits. Just a 5v power supply and:
- 2 resistors in parallel on the top circuit
- 1 resistor (the 2nd is disconnected) on the bottom circuit
You can see how much current goes through each wire.
We can see on the top circuit, 500mA goes through both of the resistors.
So, on the bottom wire of the top circuit, we get 1A total current (500mA through each resistor, so 500mA*2 resistors=1000mA).
On the bottom circuit, one resistor is disconnected, so we have 500mA traveling only through one resistor.
That also makes the total that returns on the bottom wire 500mA (the other "path", the second resistor is disconnected, that's why we lost the extra 500mA).
I hope I didn't make some mistakes in my description. You can experiment with the example here if you wish:
http://tinyurl.com/yajka884This also makes the total resistance less. A single resistor still has 10ohm of resistance. But because you have 2 resistors connected to the same power source in parallel, the total resistance is 5ohms (because more current can travel through the circuit, having 2 paths), while each individual resistor still has 10ohms. If you disconnect the second resistor, you will get 10ohms reading. If you reconnect the second transistor, again 5ohms.
The same way, if you connect two 10ohm resistors in series, you will get 20ohms, because the current will have two "barriers" to go through, or two "hills" to climb on, which is more difficult than going through just a single barrier.