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 both solenoids
- **Inner Solenoid (Solenoid 1)**:
- Length \( L_1 = 20 \, \text{cm} = 0.2 \, \text{m} \)
- Cross-sectional area \( A_1 = 4.0 \, \text{cm}^2 = 4.0 \times 10^{-4} \, \text{m}^2 \)
- Number of turns \( N_1 = 4000 \)

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