You are given four capacitors of capacitance 1/F each. How many different effective capacitors can you make with them, using one, two, three, or all four in different configurations ( in series and/or in parallel ), and what are their capacitances?A beam contains 1.9 x 10" doubly charged positive ions per cubic centimeter, all of which are moving north with a speed of 1.9 x 10- m/s. What is (a) the magnitude of the current density and (b) direction of the current density J .(c) What additional quantity do you need to calculate the total current i in this ion beam? (a) Number Units (b) (c)A certain cylindrical wire carries current We draw a circle of radius J' around its oentral axis in Figure {:1} to determine the current i within the circle. Figure (b) shows current i as a function of r2. The vertical scale is set by is = 4.0 mA, and the horizontal scale is set by r;2 = 4.5 mmz. {a} Is the current density uniform? {bl If so. what is its magnitude? in) The magnitude J(r) of the current density in a certain cylindrical wire is given as a function of radial distance from the center of the wire's cross section as J(r) = Br, where r is in meters, J is in amperes per square meter, and B = 2.14 x 10 A/m . This function applies out to the wire's radius of 2.00 mm. How much current is contained within the width of a thin ring concentric with the wire if the ring has a radial width of 12.5 um and is at a radial distance of 1.30 mm