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3. An electromagnet is made of an iron core inside an ideal solenoid that is connected to a DC emf source. The solenoid has length 6.00 cm and consists of 2000 loops of radius r₂ = 1.24 cm. The solenoid is initially carrying 3.00 A of current, which reduces at a constant rate until the current is 0 A after 4.00 seconds. The iron core inside the solenoid increases the magnetic field produced by the solenoid by a factor of 1800. Around the solenoid, there is an aluminum ring with outer radius r₁ = 2.30 cm. The aluminum ring has a rectangular cross-section with area 7.20 x 105 m²' and is at a temperature of -38.0°C. The central axis of the solenoid, iron core, and the aluminum ring are all aligned with the x-axis. a) Calculate the magnitude of the initial (when current is 3.00 A) magnetic field inside the iron core. (This answer is 1800X larger than if the solenoid was empty.) b) Calculate the magnitude of the initial magnetic flux through the ring. c) Calculate the magnitude of the induced emf in the ring. d) Calculate the resistance of the ring (Hint: length of "wire" = circumference). e) Find the direction and magnitude of the induced current in the ring. Direction, as viewed from the left: Magnitude: