Drift Velocity Calculator

Formula

The formula to calculate the Drift Velocity (u) is:

\[ u = \frac{I}{n \times A \times q} \]

Where:

\( u \) is the drift velocity (m/s).
\( I \) is the current (amps).
\( A \) is the cross-sectional area (m²).
\( n \) is the free electron density (e/m³).
\( q \) is the charge (C).

What is Drift Velocity?

Drift velocity is defined as the average speed of charged particles in a material due to an electric field acting on them. It is constant as long as the cross-sectional area and electric field stay constant along the full length of the wire or material.

Example Calculation

Consider an example where:

Current (I): 5 amps
Cross-sectional Area (A): 0.01 m²
Free Electron Density (n): \(8.5 \times 10^{28}\) e/m³
Charge (q): \(1.6 \times 10^{-19}\) C

Using the formula to calculate the Drift Velocity:

\[ u = \frac{5}{8.5 \times 10^{28} \times 0.01 \times 1.6 \times 10^{-19}} \approx 3.68 \times 10^{-4} \text{ m/s} \]

This means that the drift velocity for this example is approximately \(3.68 \times 10^{-4}\) m/s.