Consider a wire of length 4m and cross-sectional areal `1 mm^(2)` carrying of 2A. If each cubic metre of the material contains `10^(29)`free electrons, find the average time taken by an electron to cross the length of the wire.

Explanation

To solve the problem of finding the average time taken by an electron to cross the length of a wire, we can follow these steps:

### Step 1: Identify the given values
- Length of the wire (L) = 4 m
- Cross-sectional area (A) = 1 mm² = \(1 \times 10^{-6}\) m²
- Current (I) = 2 A
- Number of free electrons per cubic meter (n) = \(10^{29}\) electrons/m³
- Charge of an electron (e) = \(1.6 \times 10^{-19}\) C
...