I. Voltage and potential problems.
1.
a. What is DVAB =
VB-VAin the figure below?
What is the work required to move a 2 C charge from A to B in the figure above?
2. The charges in the diagram below are located on the corners of a square that is 6 m on each side.
a. Find the potential energy of this system .
b. Find the electric potential at P.
3. Two metal spheres are located very far apart, far enough that polarization of charge on them is nominial. The large one has radius 2r while the small one has radius r. A charge Q is placed on the large sphere and a wire is attached between the two spheres. After static equilibruim has been established, what fractional part of charge Q is located on each sphere?
II. Voltage & Power
1. Which 120 V bulb will have a filiment with the highest resistance, a 50 W bulb or a 100 w bulb?
2. What is the resistance of each of these resistors?
III. Resistors and capacitors in series and parallel.
a. Find total resistance or capacitance in a circuit.
b. Be prepared to answer any problems like the DC puzzles in ActivPhysics .
c. Draw a circuit consisting of a battery, three bulbs and a switch so that all three bulbs light before the switch is closed and only one lights when the switch is closed.
d.
III. Electric Flux and Gauss's Law
1. A hollow metal sphere has 5 C of charge placed upon it. How much of this charge is located on the interior surface of the sphere?
What does this have to do with why a Faraday's Cage works?
What does this have to do with automobiles and lightining storms?
2. An ice cream cone shaped piece of metal has an amount of charge Q placed on it. Where is the electric field the strongest?
3. A solid metal cube has charge placed on it.
Where does most of this charge end up?
where is the strongest electric field located?
4. A pyramid is located in an electric field as indicated with E perpendicular to the base. What is the electric fllux through each face?
5. An electric field is directed parallel to the vertical faces of this cube. Find the electric flux through each face of the cube.
III. Magnetic Force
1. Force on a charged particle moving in a magnetic field.
a. Find the magnitude and direction of the force on each charged particle.
2. Force on a line of current in a magnetic field.
a. Find the magnitude and direction of the force on the line of current due to the magnetic field.
b. The segment of conductor shown in the figure at right carries a current I = 3 A. The shorter section is 0.8 m long, and the longer section is 1.6 m long. Determine the magnitude and direction of the magnetic force on the conductor if there is a uniform magnetic field given by B = 2i over the region.
3. Force on one line of current due to another. Find the force each exerts on the other.
IV. Biot-Savart Law
1. Find the magnitude and direction of magnetic field at a point produced by a moving charged particle.
2. Find the magnetic field produced a given distance from a given line of current.
3. Find the magnetic field due to various configurations of current.
a. A battery establishes a steady current around the circuit illustrated below. Compass needles are placed successively at points A, B, and C along the circuit.
b. Use the Biot-Savart Law to calculate the magnitude and direction of the magnetic field at P located at the center of concentric semicircles of radii a = 5 m and b = 8 m when a current of I = 3 mA is maintained in the circuit.
V. Faraday's Law of Induction (emf induced by changing magnetic flux)
1. Find the direction of the current in the resistor R just after the switch is closed.
2. A loop of wire in the shape of a rectangle of width w and length L and a long straight wire carrying a current I lie on a tabletop as shown in the figure. Determine the total magnetic flux through the loop due to the current I.
3. The flexible loop shown in the figure has a radius of l2 cm and is in a magnetic field of strength 0.l5 T whose direction is perpendicular to the plane of the loop. The loop is grasped at points A and B and stretched until it closes. If it takes 0.2 s to close the loop, find the average induced emf in it during this time interval.
4. A long solenoid has 400 turns per meter and a radius of 10 cm. It carries a current of
I = (30 A)(1-e-1.6 t ). Inside the solenoid is a coil that has a radius of 6 cm, consists of 250 turns, and lies in a plane that is perpendicular to the axis of the solenoid. What emf is produced in this coil by the changing current ?