A long core of material with m = 100 is drawn with a force F = 10 N into a long straight solenoid through which a current I = 10 A flows. The core occupies the entire cross-section of the solenoid and is inserted to a depth significantly exceeding its diameter. Find the self-induction coefficient L of the solenoid (without a core), if its length l = 0.5 m.

Answer. Format gif