A solenoid 30 cm long is wound with 250 turns of wire. The cross-sectional area of the coil is 3.5 cm^2. What is the self-inductance of the solenoid?

The value is  

Explanation:

From the question we are told that

    The length of the solenoid is

     The number of turns is  

    The cross-sectional  area is  

Generally the self  inductance of the solenoid is  

Here   is the permeability of free space with value  

So

=>    

resonant frequency