Practice Exam 2 PHY 2140 1. What is the current through the 3.00 R resistor? ) (r3 2. In the series RC circuit shown, what is the maximum charge on the capacitor after the switch is closed? (note MR = x lo6 R ) 3. Kirchhoff s junction rule is a statement of conservation of: d y e - 4. At what distance from a long straight wire carrying a current of 6.0 A is the magnetic field due to the wire equal to the strength of the earth's field, 5.0 x loe5T? 5. At what speed v should the bar in the figure be moved to produce a current of 1A in the resistor? Assume B = 2.50 T into the page, R = 6.0 51 and the length of the bar is 1.50 m. 6. How would the self-inductance of a coil be changed if half of the length of wire were wound around the same cylinder? 7. A cube with an edge of length 1 = 0.05 m is positioned as shown. There is a uniform magnetic field throughout the region that has components B, = 5 T, By = 4 T and B, = 3 T. What is the flux through the shaded face of the cube? 8. What is the stored energy in a 0.50-mH coil carrying a current of 4.0 A? 9. What is the direction of the current induced in the resistor when the current in the long, straight wire in the figure below (1) decreases rapidly to zero and (2) is then made to flow in the opposite direction? d*r*u9k of Rc PT m jarp , lk~ +&cd uill 4 i5 rp fCmc;\ I ~ikd t ail& cc/**urt L Itr jZS b wtr~h+ L? a triangular area with a height of 30 cm and base of 40 cm as shown. The coil lies in the plane of the page and cames a current of 6.00 A flowing clockwise around it. If the coil is in a uniform magnetic field of 2.00 x T, directed towards the left of the page, what is the magnihlde of the torque on the coil.? . ICO ~i.urkb,j.C t (I a p r r 1 I. A particle with a charge of +2.0 microcoulombs and a kinetic energy of 0.090 J is fired into a uniform magnetic field of magnitude 0.10 T. If the particle moves in a circular path with a radius of 3.0 m, determine its mass. 12. Find the equivalent resistance between points a and b.