Lab 13: Electric Potential Energy

We started the day by setting up different electric circuits. The task consisted on making the bulbs dimmest or brightest as possible. For the dimmest case, we found that the batteries must be in parallel and the bulbs must be in series because the voltage of the batteries stays the same, and must be distributed through each bulb.

For the brightest case, the batteries need to be in series, and the wire connected to both bulb holder in a parallel arrangement.

Representation of both cases

We then conducted an experiment, where professor Mason heated up water through current across the heater at constant volts. 

This graph shows how the temperature of the water increases over time at constant voltage.

The experiment was repeated by doubling the voltage.

Using the equation V = IR, we said that if the voltage is doubled, then the current will also double. Then that means the power increases by a factor of 4, using the relation, P = IV, assuming that the resistor is negligible, then we have, 2P = 2I.2V.

We did an exercise that consisted in calculating the work it takes for a vehicle from point A to reach to point C. Regardless of the path it takes, the amount of work is the same. By using the formula
W = Fdcos(theta), we can say that the horizontal paths requires zero work since the angle is 90 degrees. And the vertical path is just force x distance. So the amount of work calculated was -2J. We then applied the same reasoning to the work done in an electric field. We noticed that the parallel path with respect to the electric field is greatest while the perpendicular path is zero.

This picture shows the derivation of Voltage as a function of electric field and distance.

Then we integrated the previous formula with infinite distance, we can say that the voltage is just the dot product between coulomb constant and the charge of electron over some distance r.

Then we did an exercise applying the formula V = kq/r  for some charges placed at random locations.

Finally with the previous exercise, we simulated the same problem, but using Vpython, we drew 3 charges and 3 spheres, and calculated the potential difference between them at each location.