What in electricity is like friction and tends to reduce the amount of current flow?

Answer 1

This was the first answer given:

Resistance is electricity is like friction in water flow.

but that answer was not stated correctly!

This is how the answer should actually be stated:

The effect of resistance on electricity is like the effect of friction on water flow.

Comment

Describing resistance as being 'like friction' is an analogy that is often stated but it is important to understand that it must be stated accurately, as is shown in the second example above.

The factor which is commonly known as "resistance" - which slows the speed or rate of flow of current in an electrical circuit - is caused by physical effects that are actually nothing like the physical effects which cause the factor which is commonly known as "friction" which slows the flow of water along, for example, a pipe or the bed of a river.

The analogy refers only to the fact that, if current is flowing through some material making up part of an electrical circuit, the amount of resistance present within the material has the effect of slowing down the speed or rate at which the current can flow.

The analogy is correct in the sense that, if water is flowing past a surface, the amount of roughness present on that surface causes friction which has the effect of slowing down the speed or rate at which the water can flow along that surface.

Resistance itself is actually nothing at all like either 'roughness' or 'friction': in metal conductors the amount of resistance present in any material has more to do with the availability of free electrons to act as charge carriers.