1. A square loop of wire (10-cm each side) hangs vertically, as shown here. When the current in the wire is 0.245 A counterclockwise, a scale supporting the wire indicates a downward force of 3.48x10"- N. Find the magnitude of the O O magnetic field. (5 points) B O O 2. In which direction is the (conventional) current in the wire moving? In which direction is the magnetic field in the vicinity of the wire? In which direction is the magnetic force on the wire? (5 points) 23. A helium ion (Q = +2e) whose mass is 6.6 x 10" kg is accelerated by a voltage of 3,700 V. (10 points) a. What is its speed? b. What will be the radius of curvature if it moves in a plane perpendicular to a uniform 0.340 T field? c. What is its period of revolution