A solenoid of length 20cm, area of cross- section `4.0 cm^2` and having 4000 turns is placed inside another solenoid of 2000 turns having a cross - sectional area `8.0cm ^2` and length `10 cm`. Find the mutual inductance between the solenoids.

Explanation

To find the mutual inductance between two solenoids, we can follow these steps:

### Step 1: Identify the parameters of the solenoids
- Inner solenoid (S1):
- Length (l1) = 20 cm = 0.2 m
- Cross-sectional area (A1) = 4.0 cm² = 4.0 × 10⁻⁴ m²
- Number of turns (N1) = 4000 turns

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