a) A long solenoid has 1490 turns in a length of 40.0 cm. What current has to flow through the solenoid in order to generate a magnetic field of 3.45 µT in its interior?
b) A long solenoid has 2250 turns in a length of 75.0 cm. A current of 5.65 mA flows through the solenoid. What is the strength of the magnetic field generated inside the solenoid?