The velocity of the electrons is irrelevant to the operation of a resistor. The key feature of a resistor is a substantial voltage / current ratio: i.e. it takes energy to shove electrons through the resistor. Different materials & geometries may constrain the electrons in different ways, and may yield different drift velocities.

If a circuit element requires a lot of energy to shove an electron from one end of the element to the other, it will be a "resistor" - regardless of the speed at which the electrons move. The energy input to force the electrons through the material is commonly dissipated as heat:

• Hotter materials have a higher resistivity than cool ones, since the electrons (and associated EM waves) scatter off the mobile atoms and the less-regular crystal structure.
• A narrow sample of a material will have a higher resistance than a thicker wire: Fine-gauge wires can thus function as resistors or even fuses. The electrons interfere with and repel each other, limiting their motion through the bottleneck.
• Superconductors allow all the electrons to move together as a coordinated whole, without scattering off atoms or each other - but they needn't move at an especially high speed.
• Different materials have different resistivities because their energy bands have different structures in physical and momentum space.
• Magnetic and electric fields can perturb the atomic energy levels, changing the number of electrons which can travel simultaneously in the material without interfering with each other or the atomic lattice.

The velocity of the electrons is irrelevant to the operation of a resistor. The key feature of a resistor is a substantial voltage / current ratio: i.e. it takes energy to shove electrons through the resistor. Different materials & geometries may constrain the electrons in different ways, and may yield different drift velocities.

If a circuit element requires a lot of energy to shove an electron from one end of the element to the other, it will be a "resistor" - regardless of the speed at which the electrons move. The energy input to force the electrons through the material is commonly dissipated as heat:

• Hotter metals have a higher resistivity than cool ones, since the electrons (and associated EM waves) scatter off the mobile atoms and the less-regular crystal structure. Different types of materials may have different temperature-dependence.
• A narrow sample of a material will have a higher resistance than a thicker wire: Fine-gauge wires can thus function as resistors or even fuses. The electrons interfere with and repel each other, limiting their motion through the bottleneck.
• Superconductors allow all the electrons to move together as a coordinated whole, without scattering off atoms or each other - but they needn't move at an especially high speed.
• Different materials have different resistivities because their energy bands have different structures in physical and momentum space.
• Magnetic and electric fields can perturb the atomic energy levels, changing the number of electrons which can travel simultaneously in the material without interfering with each other or the atomic lattice.