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Magnetism labs

Why are we studying magnetism and electricity? Electromagnetism

We’ll be mentioning an electromagnetic field.
What exactly is a “field”?: What are fields?

Assignment: Uncover the connections between electricity and magnetism. Go to each of the 7 lab stations. Follow the instructions and safety procedures. Take careful notes at each station. Click here for the lab report rubric.

  • Write a one paragraph introduction. Don’t discuss specific procedures, rather, give an overview of the lab. Why study magnetism and electricity in the first place? (See first link, above)

  • Write the procedures and materials for one of these sections.

  • Carefully draw (use rulers, protractors) or draw on a computer, the setup for this station. Label each part as best you can.

  • Data: Clearly and accurately describe what you observed for this station.

  • Conclusions: Review your notes for all 7 lab stations. What connections did you observe between electricity and magnetism? In your own words, come up with some rules to explain how they are related?

Format: Use a 12 point font in Courier, Arial or Times New Roman.  1” margins, double-spaced, spell check and grammar check your work. Do not create a separate cover page.

Late papers lose 2 points/day.

In order to receive credit for the lab, one must safely follow the procedures. One will receive no credit for the lab if one doesn’t follow directions and merely played with equipment; or engaged in unsafe procedures/horseplay.

Station 1 electromagnet

We don’t see magnetic fields directly – but we can see their effect. By putting a tiny piece of metal near our electromagnet, we can see if/how it is moved. If we trace out the motion of many test particles, we would generate a pattern that would look something like this:

Station 2 St. Louis Motor/Induction Motor

Look at the animations here to see how motors work. http://www.animations.physics.unsw.edu.au/jw/electricmotors.html

Also see the explanation at Hyperphysics DC Motors

External resources

http://www.csun.edu/scied/1-demo/induction_motor/

https://sciencefirst.com/download/science-first-manuals/physics-lab-equipment/24-1155%2010-155%20615-4700%20st%20louis%20motor.pdf

Station 3
a stand with wire running through it, several compasses, DC voltage source, a magnet, and connecting wire

Oersted magnetic field long wire

Station 4 – Ring launcher – Elihu Thomson apparatus

Demonstrates Lenz’s law and effects of electromagnetically induced currents.

When the switch is flipped, the suddenly-increasing magnetic field induces current to flow in the ring. The current creates an magnetic field opposing the original field. The field from the post and the field from the induced current in the ring repel each other just as north poles of two bar magnets would. It is this strong repulsion that launches the ring into the air.

If the first aluminum ring is replaced by another one that has a split completely down one side, then can a steady current be induced in the ring? No, because the ring doesn’t form a complete circuit. That means that when this ring is placed on the launcher and the magnetic field through it is increased, no current can be induced in the ring. Therefore, the ring can’t produce its own magnetic field. No induced magnetic field … no repulsion, and the ring never leaves the launcher.

http://demos.smu.ca/index.php/demos/e-n-m/51-rail-gun

ring launcher Elihu Thomson apparatus

more resources:

Elihu Thomson – One of the greats like Thomas Edison and Nikola Tesla

 

Station 5 – neodymium homopolar motor

https://en.wikipedia.org/wiki/Homopolar_motor

Station 6 -Faraday’s law of induction

Coils of wire, magnets, an ammeter, and banana-to-alligator wires.

Station 7 – Lenz’s law demo

Good step by step explanation here: http://regentsprep.org/regents/physics/phys08/clenslaw/

 

2016 Massachusetts Science and Technology/Engineering Curriculum standards

7.MS-PS2-5. Use scientific evidence to argue that fields exist between objects with mass, between magnetic objects, and between electrically charged objects that exert force on each other even though the objects are not in contact.

7.MS-PS3-2. Develop a model to describe the relationship between the relative positions of objects interacting at a distance and their relative potential energy in the system. {Examples could include changing the direction/orientation of a magnet.}

HS-PS2-5. Provide evidence that an electric current can produce a magnetic field and that a changing magnetic field can produce an electric current.

HS-PS3-1. Use algebraic expressions and the principle of energy conservation to calculate the change in energy of one component of a system when the change in energy of the other component(s) of the system, as well as the total energy of the system including any energy entering or leaving the system, is known. Identify any transformations from one form of energy to another, including thermal, kinetic, gravitational, magnetic, or electrical energy, in the system:

Chemical potential energy is stored in our muscles as ATP; this is transformed into translational kinetic energy (KE) as we move our hand; this gives the magnet it’s own KE.  The magnet’s moving magnetic field then creates electrical energy in the coil, which we measure with an ammeter, thus addressing HS-PS3-3.

HS-PS3-3. Design and evaluate a device that works within given constraints to convert one form of energy into another form of energy.

HS-PS3-5. Develop and use a model of magnetic or electric fields to illustrate the forces and changes in energy between two magnetically or electrically charged objects changing relative position in a magnetic or electric field, respectively.

Board of ed

Next Gen Science Standards

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