Electric current flow, like that of water flow is limited by the size and characteristics of the conductor it is flowing through. 

If you increase the surface area of a conductor you will decrease the resistance, similarly, if you decrease the surface area of a conductor you will increase the resistance to current flow.

Fig 3

Resistance in a circuit generally remains constant unless a variable resistor is fitted.

• If the resistance is increased while the voltage is held constant, the flow of electrons will be reduced.

 

• If the voltage is reduced while the resistance is held constant the flow of electrons will be reduced.

 

• If the resistance is reduced while the voltage is held constant, the flow of electrons will be increased.

 

• If the voltage is increased while the resistance is held constant, the flow of electrons will be increased.


Consider a balance scale with Voltage and Resistance as the two weights and Current flow as the reading on the scale see the illustration fig 3 above. if one of the two variables is changed this has an immediate impact on the reading of the scale causing the needle to swing in the direction of which ever arm of the balance is has an increased load.