Answer each question in one or two complete sentences, mathematical expressions and diagrams as necessary. Make certain you explain your logic. Answers without clear work receive no credit. 1 - = k = 9 x 109 Nm2 AV = E; ATTEO C2 ; E = k 2; F = qE;V = k-; Art Po + 1 x 10-7_ 7; dB = Ho qu xr 4 TT 471 73 ; dB = Holdl x r -; B = Ho i 47 23 ;M = IA e = 1.6 x 10-19C; me = 9.11 x 10-31kg ; mp = 1.67 x 10-27kg 4. (15) A piece of wire is bent into a loop with two concentric arcs as shown below. The inner arc has a radius of R. The outer arc has a radius of 3R. There is a current I introduced into the loop. A) What is the direction of the magnetic field at the dot shown on the diagram? B) Which pieces of the loop contribute to the magnetic field at the point of interest? Explain. C) Write an integral expression to determine the magnetic field at the dot (center of curvature of both arcs). 5. (10)A bar magnet is hung by a string tied to its center so that it is horizontal. It orients so that the north pole of the bar magnet is pointing north (i.e. it acts as a compass). You charge a plastic rod such that it develops a positive charge. You bring this near the south pole of the magnet and it attracts the magnet. You are going to bring it near the north pole of the magnet, what will happen and why