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Physics 212Midterm 2Form A1. A wire contains a steady current of 2 A. The charge that passes a cross section in 2 s is:A. 3.2 × 10-19CB. 6.4 × 10-19CC. 1 CD. 2 CE. 4 C2. In a Physics 212 lab, Jane measures the current versus voltage characteristics for two nichromewires and makes the graph shown. The wires are of the same diameterbut have differentlengths. Which of the following statements is correct?3. The current density across a cylindrical conductor of radius Rvaries according to the equation J=J0(r/R), where ris the distance from the central axis. Thus, the current density is zero at the axis (r= 0) and increases linearly to J0at the surface (r= R). Calculate the current in terms of J0and R.A. i= (πR2J0)/2B. i= (2πR2J0)/3C. i= (πR2J0)/6D. i= (πR3J0)/3E. i= (πR3J0)/64. A wire is 1 m long and 1 × 10-6m2in cross-sectional area. When connected to a potentialdifference of 2 V, a current of 4 A exists in the wire. The resistivityof the wire material is:Page 1
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