A 3.0-μC positive point charge is located at the origin and a positive point charge is located at Find the coordinates of the point where the net electric field strength due to these charges is zero.

If the current density in a wire or radius R is given by J = kr, 0 < r < R, what is the current in the wire?

A 1.0 m long piece of coaxial cable has a wire with a radius of and a concentric conductor with inner radius The area between the cable and the conductor is filled with a dielectric. If the voltage drop across the capacitor is when the line charge density is find the value of the dielectric constant.

Two identical small conducting spheres are separated by 0.60 m. The spheres carry different amounts of charge and each sphere experiences an attractive electric force of 10.8N. The total charge on the two spheres is -24 μC. The two spheres are now connected by a slender conducting wire, which is then removed. The electric force on each sphere is closest to

If a current of 2.4 A is flowing in a cylindrical wire of diameter 2.0 mm, what is the average current density in this wire?

A thin, circular disk of radius 30.0 cm is oriented in the yz-plane with its center at the origin. The disk carries a total charge of +3.00 μC distributed uniformly over its surface. Calculate the magnitude of the electric field due to the disk at the point along the x-axis.

When a voltage difference is applied to a piece of metal wire, a current flows through it. If this metal wire is now replaced with a silver wire having twice the diameter of the original wire, how much current will flow through the silver wire? The lengths of both wires are the same, and the voltage difference remains unchanged. (The resistivity of the original metal is 1.68 × 10-8 Ω • m, and the resistivity of silver is 1.59 × 10-8 Ω • m.)

A small glass bead has been charged to 8.0 nC. What is the magnitude of the electric field from the center of the bead? (k = 1/4πε0 = 8.99 × 109 N • m2/C2)

The voltage and power ratings of a particular light bulb, which are its normal operating values, are 110 V and 60 W. Assume the resistance of the filament of the bulb is constant and is independent of operating conditions. If the light bulb is operated with a current that is 50% of the current rating of the bulb, what is the actual power drawn by the bulb?

A metal cylinder of radius 2.0 mm is concentric with another metal cylinder of radius 5.0 mm. If the space between the cylinders is filled with air and the length of the cylinders is 50 cm, what is the capacitance of this arrangement? (k = 1/4πε0 = 8.99 × 109 N • m2/C2)