What will be the effect on the self-inductance of a long solenoid, if the number of turns of a solenoid is made 3 times?

Explanation

To determine the effect on the self-inductance of a long solenoid when the number of turns is increased to three times, we can follow these steps:

### Step 1: Understand the formula for self-inductance
The self-inductance \( L \) of a solenoid is given by the formula:

\[ L = \frac{\mu_0 N^2 A}{l} \]
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