ELI5, what is electrical resistance?
In: Physics
It is the natural tendency for electrons to resist change in their current state. Different material has different resistances: gold vs copper, for example.
Think of being in a pool and trying to punch, then think of doing it in open air. Both water and air are ‘fluids’, but water has more resistance.
To illustrate it, take a spoon and wave it in the air. It probably doesn’t take a lot of effort (force) to do this. Now put the spoon in a glass of water and try to stir the water. Then put the spoon in a jar of honey or peanut butter and try to stir it. It will require more and more effort to stir the fluid going from air to water to honey.
Electrical resistance is the same effect but rather than force it is electrical potential (measured in volts) and rather than the speed of the spoon, it is the current (measured in amperes). A material with high electrical resistance requires a lot of voltage (force) to generate the same amount of current (motion) while the reverse is true of a material with low electrical resistance.
Imagine a hose spraying water. There is 100 gallons of water per minute spraying out of the hose (that is the current). If the hose has a small diameter (that is the resistance or Ohms), then the water pressure (that’s the voltage) will be very high. If the hose’s diameter is large (low resistance) then the pressure (Voltage) will be lower.
Resistance describes a material’s ability to resist the flow of electrons. Resistance occurs when electrons collide with atoms. The amount of these collisions depends on the material and its temperature, thickness and length.
The collisions manifest themselves as a rising temperature of the conductor and sometimes as light. We often use components called resistors to purposely give the circuit some resistance in order to prevent too much current from reaching vulnerable parts of the circuit or to produce some light and heat. The unit of resistance is ohm (Ω).
[How electricity works](https://joonasjokinen.fi/en/blog/posts/how-does-electricity-work)
You want to fill a bucket with water from a large water deposit. Now imagine these 3 options :
– you just open the tap and let the water flow free from the water deposit. The bucket fills quickly.
– you open the tap but attach a pipe full of cobblestones . The water flows but slower, since it has to go around all the little stones inside the pipe, taking more time to fill the bucket.
– now you fill the pipe with sand, or cotton. The bucket will eventually fill too, but taking a long time.
This opposition that the water finds to flow thru a pipe is pretty much like electrical resistance for electric charges.
So far I don’t think anyone has actually answered your question. Resistance is the inability or lack of ease at which electricity (electrons) moves through substances. It moves easier when there are lots of free electrons available. How do you get more free electrons? Make the substance larger. ( small wire to large wire) . Get a better conductor. (copper and silver are good conductors) Add something to the conductor. Stand in a wet basement with sweaty hands and touch a hot wire and you’ll be lucky to survive. Do the same thing with rubber boots and calloused dry hands and you won’t be shocked.
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