# resistance in a parallel circuit

ive tried watching lots of videos but i still dont understand why the resistance of a parallel circuit decreases the total resistance?? (gcse) could someone explain this to me please!
In parallel the resistance is always lower than either of the resistors on it's own.

If you consider starting with a single resistor, adding another resistor in parallel will create an additional route for current.

More current at the same voltage means lower effective resistance of the pair.
Original post by Joinedup
In parallel the resistance is always lower than either of the resistors on it's own.

If you consider starting with a single resistor, adding another resistor in parallel will create an additional route for current.

More current at the same voltage means lower effective resistance of the pair.

how is there more current? i thought it was split between the loops
Original post by anonymous.2003
how is there more current? i thought it was split between the loops

Yeah.

If you start with a 10V battery and a 10 ohm resistor, that resistor passes 1Amp.

If you stick another resistor in parallel that will also pass some current additional to the 1A going through the first resistor.
Consider a highway analogy. In a parallel circuit, each additional resistor is like adding an extra lane to the highway. In the usual circumstances, traffic (or electrical current) would be slowed down due to congestion (resistance), but as you add more lanes (resistors), each vehicle (electron) gains access to its own personal lane.

But here's where the analogy takes a twist. Instead of each lane simply providing more room for traffic, it also somehow magically reduces the number of cars (electrons) in each lane. So, with each added resistor (lane), the amount of electrical traffic (current) in each lane (resistor) decreases. This diminished traffic consequently reduces the speed limit (resistance) on each lane (resistor) because fewer cars (electrons) cause less wear and tear on the road (resistor), which is what the speed limit (resistance) is designed to prevent.

And there you have it: with each added resistor in a parallel circuit, there is less electrical traffic in each resistor, causing less wear and tear, which lowers the speed limit (resistance). The result is a decrease in total resistance in the circuit.
Original post by kek6969
Consider a highway analogy. In a parallel circuit, each additional resistor is like adding an extra lane to the highway. In the usual circumstances, traffic (or electrical current) would be slowed down due to congestion (resistance), but as you add more lanes (resistors), each vehicle (electron) gains access to its own personal lane.

But here's where the analogy takes a twist. Instead of each lane simply providing more room for traffic, it also somehow magically reduces the number of cars (electrons) in each lane. So, with each added resistor (lane), the amount of electrical traffic (current) in each lane (resistor) decreases. This diminished traffic consequently reduces the speed limit (resistance) on each lane (resistor) because fewer cars (electrons) cause less wear and tear on the road (resistor), which is what the speed limit (resistance) is designed to prevent.

And there you have it: with each added resistor in a parallel circuit, there is less electrical traffic in each resistor, causing less wear and tear, which lowers the speed limit (resistance). The result is a decrease in total resistance in the circuit.

thanks Kek6969!
Original post by anonymous.2003
ive tried watching lots of videos but i still dont understand why the resistance of a parallel circuit decreases the total resistance?? (gcse) could someone explain this to me please!

In a parallel circuit, there are more loops the current gets through. That is to say, there is not one route the current leads, but more. Same with the resistances: they are a part of many loops, so for many routes and each route stands for its own.

That is the difference to the series circuit: it has one loop for all the resistances in. That is an entire route for them alone. In a parallel circuit instead, the total resistance are divided by many loops. Every single loop is an own route. The resistances have no additional effects to the current compared to the series circuit, as they have not the same route they work on. Thus the total resistance is decreased.