Finding Electric Fields

8. A sphere of radius R1 carries a uniform charge density p throughout its volume except for a small spherical hollow volume of radius R2 located at distance a from the center (and fully contained within the larger sphere). a) Calculate the electric field E at the center of the hollow sphere. [Be careful, you can’t just apply Gauss’s law here. Qenclosed may be zero, but you can’t do the surface integral. The field is NOT zero. b) Calculate the potential at the same point.

Resistors

Resistors. See attached file for full problem description.

Resistors

Resistors. See attached file for full problem description.

Electric Current

In a certain electron beam, there are 5.0 x 10^6 electrons per cubic centimeter. Suppose the kinetic energy of each electron is 10 keV and the beam is cylindrical with a diameter of 1 mm. (a) what is the velocity of an electron in the beam? (b) find the beam current.

Electric Current

What is the potential difference across one wire of a 30-m extension cord made of 16-gauge copper wire carrying of 5 A?