A solenoid is wound with 970 turns on a form 4.0 cm in diameter and 50 cm long. The windings carry a current I in the sense that is shown in the figure. The current produces a magnetic field, of magnitude 4.3 mT, near the center of the solenoid. Find the current in the solenoid windings. (40 = 4x x 10-7 T . m/A) 4.0 cm O 2.2A O 1.8 A O 2.0A O 1.5 A O 1.3AA conducting bar slides without friction on two parallel horizontal rails that are 50 cm apart and connected by a wire at one end. The resistance of the barancl the rails is constant and equal to 0.10 D. A uniform magnetic field is perpendicular to the plane of the rails. A 0.0807N force parallel to the rails is required to keep the bar moving at a constant speed of 0.50 mils. What is the magnitude of the magnetic field? :3 0.36T O 0.93 T o 0.25 T o 0.10T o 0.54 T