Last week the “Contemporary Science and Innovation” class experimented with Lego robots to understand Faraday’s Law. Farady’s Law is a change in magnetic environment or flux of a coil of wire which will cause the voltage (emf) to be “induced” in the coil, generating electricity. The greater the change in magnetic flux, the greater the currents and voltages will become. The modification is produced by altering the magnetic field strength, moving a magnet away or towards the coil. Which moves the coil into or out of the magnetic field, rotating the coil relative to the magnet. The induced emf in the coil is equal to the negative rate of change of magnetic flux times the number of turns within the coil. It involves the interaction of charge with the magnetic field. Faraday’s law is the central operating principle of transformers, inductors, and many types of generators, electrical motors, and solenoids (coil wound around helix). EMF is Electromotive Force which is the voltage developed by any source of electrical energy such as a battery or a motor. The force is not a mechanical force (measured in newtons), but a potential or energy used per unit of charge (measured in volts). In electromagnetic initiation, emf can be defined around a closed loop as the electromagnetic work that is transferred to unit of change if it travels once around the loop. While the charge journeys around the loop, it can simultaneously loose the energy through resistance into thermal energy.

In this lab the class had a generator (or a magnet inside a coil of wire) that was housed in a flashlight body with a positive and negative wire (voltage probe) connecting to the NXT. The NXT again is a programmable robot kit released by LEGO Company that our class uses for experiments. All of the data throughout the experiment was recorded into a Microsoft Excel sheet. The first task we did was look over the VI works program to understand exactly what was expected of us and how the VI program recorded the data. It records the data by monitoring the increase or decrease of voltage at an exact moment to calculate the total voltage in the end.

To start in teams the class set up the lab by plugging in the positive and negative wires to the voltage adaptors and plugging it into the NXT. After completing the setup the class opened the VI program and began the lab. The task is to count the number of shakes of the generator, in a 30 second time interval, with the voltage that the generator produces.  The first run that the group did was without shaking the generator and leaving it flat on the desk. This was done so that a stable result could be found within the readings, with the sum of voltage as 0.09. During the second run the group shook the generator 20 times in 30 seconds and got the sum of the numbers as 0.16. The number is so low because the generator did not move. In the third round our group did 35 shakes in 30 seconds with the sum of 0.41 which was higher than our first result because the generator was moved back and forth. The third test 65 shakes in 30 seconds with the sum voltage of 0.51. And the final run was 103 shakes in 30 seconds with the summation of 4.55 volts. The last run jumped significantly and it is not determined if the group counted correctly or too slow which would change the outcome.

The numbers rose as the group shook the generator faster because the generator didn’t have to work as hard to travel from one end to the next because the motion was faster. Also because the greater the change in magnetic flux, the greater the currents and voltages will become. When the currents and voltages raise the numbers raise and they raise because the number of shakes increase.

This lab is extremely useful to understand just how much energy is used to create power or electricity. It gives a perspective of how voltage works and the usefulness of it. This experiment also shows that if the United States updated their power grid maybe they wouldn’t have to work so hard at maintaining it and maybe they will use less energy and resources. If the power grid was hooked up to something more energy efficient and reliable we wouldn’t have to worry about power plants and the negative effects and reputation that come with them. Also if coils and wires were concealed better (in better casings) maybe they would last longer and protect against fire.