Physics is a subject that students can enroll in for their last 2 years of high school in Canada. Physics can be one of the most interesting subjects, but students can shy away from the class because of the unknown. We have created a series of articles around physics topics to get students interested in physics. This article focuses on magnetism and electromagnetism. Students can then after reading make the informed decision if high school physics class is right for them.

Students are also encouraged to check out potential students of the High School Physics Syllabus and provide them with all the information that will be covered in this subject in order to help them make an educated decision and decide if this high school subject is for them.

Magnetic Fields

Magnetism is perhaps a concept most students can understand quite easily. We've all played with magnetics as kids. Magnets have two opposite poles, the north-seeking pole of a magnet is known as the north pole and the south-seeking pole is commonly referred to as the south pole.

Permanent Magnets

Iron, steel, nickel and cobalt are all magnetic materials that are attracted to either pole of the magnet. Permanent magnets are most commonly made of iron and produce their own magnetic field that cannot be turned off.

Induced Magnets

These magnets are very different from permanent magnets due to the fact that they only become a magnet when placed in a magnetic field. After it is removed from the magnetic field, its magnetism is quickly lost. They can only be attracted to other magnets and they cannot repel.

What is a Magnetic Field?

cardinal directions
While humans may not be able to determine the Earth's magnetic fields, a simple tool like a compass can do the work for us using the four cardinal directions. (Source: pixabay)

 

Students will learn the basics of magnetic fields. They are invisible to the naked eye and can only be detected using a small tool known as a compass. Students will also draw a magnetic field during their studies.  Primary characteristics of drawing a magnetic field include the fact that magnetic field lines never touch, the closer the lines = stronger the magnetic field and the lines drawn have arrowheads so that onlookers understand in which direction the force is going.

Electromagnets

Electromagnets can be observed most often in household devices such as electric bells and door locks that can both be controlled with a remote. The most simple electromagnets are created by coiling wire around an iron nail. Solenoids are wires coiled up in a spiral shape and play an important part in the creation of an electromagnet due to the fact that a solenoid with an iron core is called an electromagnet. These concepts can hard at first to understand. Hiring a physics tutor to help you is never a bad idea.

The Motor Effect

In this section, students next analyze and calculate the motor effect which is basically two magnetic fields interacting and creating a force that pushes the wire at right angles. The motor effect can be calculated using the following equation:

                                                      force = magnetic flux density x current x length    or     F = B~I~l

Examples and questions are observed by pupils to better understand the use of the motor effect in the scientific discipline of physics. Consider taking physics courses online here. An electric motor can be made using the force a coil of wire carries a current into a magnetic field that tends to make it rotate. Electric motors have many different parts that need to be explained in order to correctly understand their function.

Electromagnetic Induction

bicycle lights
The backlight that is featured on some bikes is known as a dynamo and is a type of DC generator. (Source: pixabay)

Electromagnetic induction or the generator effect is when a coil of wire is moved in a magnetic field or a magnet is moved in a coil of wire to create a potential difference that is needed to make an electric current flow. Students also take time to understand more about the current of induced potential and how it depends on the direction of the movement and how the direction is reversed when the magnet is taken out of the coil.

AC Generator

AC stands for alternating current. An AC generator is a device that produces a potential difference. These generators are used in cars every day to keep the battery charged. A simple AC generator can be made up of simple elements such as a coil of wire that rotates around a magnetic field.  The output of an alternator can be featured on a potential difference-time graph with the voltage on the vertical axis and time on the horizontal axis.

DC Generator

DC stands for Direct current. A DC and AC generator both produce potential differences. A basic DC generator is made up of a coil of wire rotating in a magnetic field using a split-ring commutator. Some bicycles have a DC generator known as a dynamo that runs the lamps while the wheels are turning. In a dynamo, the current to the external circuit always flows in the same direction and its output can be observed on a difference-time graph that has the potential difference or voltage on the vertical axis and the time on the horizontal axis.

Transformers

using a transformer
Transformers change the potential difference of an alternating current. They can be used for imported appliances when living in a foreign country. (Source: pixabay)

Transformers are a useful tool for those living overseas where the voltage can be different. They can change the potential difference or voltage of an alternating current.  A step-up transformer increases the voltage and a step-down transformer decreases the voltage. A basic transformer that is most commonly used is made up of two coils of wire: a primary one from the AC input and a secondary coil to the AC output.  Transformers can only work will alternating current and students learn more about its functions when it is working.

Calculating potential differences can be done using the following equation:

\frac{primary~voltage}{secondary~voltage} = \frac{number~of~turns~on~primary~coil}{number~of~turns~on~secondary~coil}

It is also important to note that pupils will learn how to calculate a transformer's power transfer:

power = potential difference x current

The power is measured in watts, the potential difference is calculated in volts and the current is gauged in amps.

Sample Exam Questions

Questions on the assessments from the High School Physics Syllabus include many different types of questions that all aim to test the knowledge of students. When pupils decide to take time and analyze examples of the different kinds of questions that will be considered on the examination, they reduce stress and increase performance results.

Here are the types of questions considered on the High School Physics Syllabus examination: 

  • Multiple choice questions: the simplest to complete because all students have to do is read the different options and check the right box,
  • One and two mark questions: these questions start off with keywords such as "describe" or "explain" and these questions may have diagrams or graphs to consider,
  • Three and four mark questions: practically the same as the aforementioned questions, however, longer answers are required,
  • Maths questions: students maths skills are tested and they may sometimes be asked to draw a graph,
  • Practical questions: these questions are based on the knowledge acquired while completing the required practical activities,
  • Six mark questions: many students find these questions to be the most difficult on the assessment due to the long and logical answers that are required,
  • Equations: this part requires test taskers to remember the different equations that were taught during class time.

Learning about some of the most powerful forces in the world, magnetism and electromagnetism, can helpfully prepare students for a future scientific career or provide the acquiring of essential physics topics for those with scientific interests.

There are lots of interesting topics in physics. Students that find themselves having trouble can always use a tutor.  Superprof has 100s of physics tutors in Canada that are ready to help you. They have the experience and knowledge to teach you the best way possible. Superprof also offers lessons online and in-person giving you the freedom and flexibility to learn when you want to learn.

The essential physics topics that cover the High School, other than magnetism and electromagnetism, are energy, electricity, particle model of matter, atomic structure, forces, waves and space physics.

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Chester

You can usually find me writing at a cafe sipping on coffee or working out at the gym. I fell in love with writing a few years ago and have never looked back. I love being able to share my words with the world.