Drift Velocity Calculator
Calculate the drift velocity of charge carriers in conductors and semiconductors
Calculate Drift Velocity
Electric current flowing through the conductor
Cross-sectional area of the conductor
Number of charge carriers per unit volume
Electric charge on each carrier (electrons: 1e)
Drift Velocity Results
Formula used: u = I / (n × A × q)
Input values: I = 0.000e+0 A, A = 0.000e+0 m², n = 0.000e+0 carriers/m³, q = 1.602e-19 C
Note: This is the average velocity of charge carriers, not the speed of electrical signal propagation
Velocity Analysis
Example Calculation
Copper Wire Example
Material: Thin copper wire
Current (I): 10 A
Cross-sectional area (A): 1 mm² = 1×10⁻⁶ m²
Number density (n): 8.5×10²⁸ electrons/m³
Charge (q): 1 elementary charge = 1.6×10⁻¹⁹ C
Calculation
u = I / (n × A × q)
u = 10 / (8.5×10²⁸ × 1×10⁻⁶ × 1.6×10⁻¹⁹)
u = 10 / (1.36×10⁴)
u = 7.35×10⁻⁴ m/s ≈ 0.735 mm/s
This is surprisingly slow - about 2.6 mm/hour!
Key Concepts
Drift Velocity
Average velocity of charge carriers
Much slower than signal propagation
Electric Current
Flow of electric charge
Measured in Amperes (A)
Number Density
Carriers per unit volume
Material-dependent property
Typical Number Densities
Quick Facts
Electrons in copper move at ~0.1 mm/s
Electrical signals travel at ~200,000 km/s
Higher current = higher drift velocity
Smaller wire area = higher drift velocity
Understanding Drift Velocity
What is Drift Velocity?
Drift velocity is the average velocity that charge carriers (typically electrons) achieve in a conductor when an electric field is applied. Despite the fast response of electrical devices, individual charge carriers move surprisingly slowly.
Why is it Important?
- •Understanding current flow in conductors
- •Designing electronic components
- •Analyzing semiconductor behavior
- •Understanding material properties
Formula Explanation
u = I / (n × A × q)
- u: Drift velocity (m/s)
- I: Electric current (A)
- n: Number density of charge carriers (/m³)
- A: Cross-sectional area (m²)
- q: Charge per carrier (C)
Key Insight: Electric signals propagate at near light speed through the electromagnetic field, while individual charge carriers move much slower.