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.

Coulomb’s law: In the figure, all the charges are point charges and the charge in the middle is Q = -3.1 nC For what charge will charge  be in static equilibrium?

Resistivity: A cylindrical wire has a resistance R and resistivity

Internal battery resistance: What is the maximum current that can be drawn from a 1.50 V battery with an internal resistance of 0.30 ohm?

Resistivity: You are given a copper bar of dimensions 3 cm × 5 cm × 8 cm and asked to attach leads to it in order to make a resistor.(a) If you want to achieve the SMALLEST possible resistance, you should attach the leads to the opposite faces that measureA) 3 cm × 5 cm.B) 3 cm × 8 cm.C) 5 cm × 8 cm.D) Any pair of faces produces the same resistance.(b)  If you want to achieve the LARGEST possible resistance, you should attach the leads to the opposite faces that measureA) 3 cm × 5 cm.B) 3 cm × 8 cm.C) 5 cm × 8 cm.D) Any pair of faces produces the same resistance.

RC circuits: A  4.0 mF capacitor is discharged through a  4.0 k

Gauss’s law: The figure shows four Gaussian surfaces surrounding a distribution of charges(a) Which Gaussian surfaces have an electric flux of -q/

Power: A 110 V hair dryer is rated at 1200 W.  What current will it draw when operating from a 110 V electrical outlet?

Resistors in combination: A 5.0

Determine the financial statement Element to which the following account belongs:  Sales Tax Payable