A solenoid of infinite length consists of a single layer 1000 turns per unit length of a wire carrying a current of 2mA. Calculate the magnetic field on the axis at the middle of the solenoid.

Explanation

To solve the problem of calculating the magnetic field at the axis of an infinite solenoid, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Values:**
- Number of turns per unit length (n) = 1000 turns/m
- Current (I) = 2 mA = 2 × 10^(-3) A
- Permeability of free space (μ₀) = 4π × 10^(-7) T·m/A
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