Using Ampere's circuital law, obtain an expression for the magnetic field along the axis of a current carrying solenoid of length l and having N number of turns.

Explanation

To derive the expression for the magnetic field along the axis of a current-carrying solenoid using Ampere's Circuital Law, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Solenoid**:
- A solenoid is a long coil of wire with many turns (N) and carries a current (I). The length of the solenoid is denoted as \( l \).

2. **Direction of the Magnetic Field**:
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