2) A certain plasma arc (welding arc) can be approximated as a cylinder of high- temperature conducting gas that extends from the welding rod tip to the work-piece. This conducting cylinder can be assumed to have a constant circular cross-section with a radius of R = 4.50 mm which carries a current along its length having a density given by:

The electron beam generated in a high energy electron accelerator has a circular cross section of radius R=1 mm, and a current intensity of I=8 μA. How long would it take for Avogadro's number of electrons to emerge from the accelerator?

5. Consider two (1 and 2) wires both having constant circular cross sectional areas: wire 1 has diameter = d, ; wire 2 has diameter = d. Potential differences are applied across each wire so that they both carry current. The current in wire 1 is I, and in wire 2 it is I, ; the the magnitude of the current density in wire 1 is J, and in wire 2 it is J,. If I,= I, and J, = (2) J, then wire diameters must be such that d, = (?) d. a. 2/2 b. V212 c. 2 d. V2 e. V214

the current density present in a conductor is 570/m^2. what is the current flowing the conductor of the radius of cross sectional area is 0.34 ft

O Macmillan Learning Two insulated copper wires of similar overall diameter have very different interiors. One wire possesses a solid core of copper, with a circular cross section of radius 3.03 mm. The other wire is composed of 19 strands of thin copper wire bundled together. Each strand has a circular cross section of radius 0.606 mm. The current density J in each wire is the same. J = 1350 A/m² How much current does each wire carry? solid wire current: A solid wire resistance: The resistivity of copper is p = 1.69 × 10-8 Q.m. What is the resistance of a 1.75 m length of each wire? stranded wire current: Ω stranded wire resistance: A Ω

A certain cylindrical wire carries current. We draw a circle of radius r around its central axis in Figure (a) 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 = 5.3 mA, and the horizontal scale is set by r² = 4.7 mm². (a) is the current density uniform? (b) If so, what is its magnitude? (a) (b) Number i Units i (mA) (()) (a) -² (mm²) (b)

Consider a hollow spherical conductor of inner radius a and outer radius 3a. The conductivity (sigma) is a function of r, measured from the center of the sphere: sigma = c / r, where a < r < 3a and c is a constant. a) If we apply a potential difference V between it's inner and outer surfaces, with the inner surface at a higher potential, find the resulting current density j and the electric field E as a function of r. b) Find the resistance R of the spherical resistor

The current density in a cylindrical wire of radius 3R is given by J=J0 (1 - r2/R2). Density is parallel to the axis. Find the total current passing through the section perpendicular to the axis.

A Van de Graaff generator produces a 2 MeV beam of deuterons, which are heavy hydrogen nuclei containing one proton and one neutron.If the electric current of the beam is 10 μA, find the separation distance between the deuterons?

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