hi can somebody help me with this??

a solenoid of length L and radius R carries a current I in its N turns. what is the total energy stored in the magnetic field within the solenoid?

Compute the inductance L using the solenoid formula. You should be able to find the formula in your text or with a web search. To avoid confusion of symbols, call the length l.

The energy in the magnetic field is (1/2) L I^2.

I will try to find you a reference for computing the solenoid inductance and post it later

You can find the solenoid inductance formula at

ty i got it!

You're welcome! I'm glad you were able to find the solenoid inductance formula. If you have any more questions, feel free to ask!