MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Internal battery resistance: In the figure, when the terminal voltage Vab of the battery is equal to 20 V, how much current passes through the battery, including its direction? 1) A) 6 A, from a to b B) 5 A, from a to b C) 4 A, from b to a D) 5 A, from b to a E) 4 A, from a to b 2) Internal battery resistance: The emf and the internal resistance of a battery are as shown in the figure. When the terminal voltage Vab is equal to 17.4 V, what is the current throug battery, including its direction? 2) A) 6.8 A, from b to a B) 8.7 A, from b to a C) 16 A, from b to a D) 6.8 A, from a to b E) 8.7 A, from a to b 3) Current density: A proton beam that carries a total current of 1.3 mA has 10.0 mm diameter. The current density in the proton beam increases linearly with distance from the center. This is expressed mathematically as J(r) = J0 (r/R), where R is the radius of the beam and J0 is the current density at the edge. Determine the value of J0. A) 6.2 A/m2 B) 17 A/m2 C) 25 A/m2 D) 12 A/m2