GENERAL PHYSICS 2 - SEMI FINALS Flashcards
Magnetism
The ability to cause attractive and repulsive phenomena in other entities is referred to as magnetism, which is a category of physical characteristics that are mediated by a magnetic field.
Magnetic Force
One of the four fundamental forces of nature, the electromagnetic force, results in the magnetic force, which is brought about by the motion of charges. When two charge-containing objects move in the same direction, a magnetic attraction pulls them together. Similar to this, there is a repulsive force between charged objects moving in opposite directions.
Magnetic Properties
The conventional approach to determining the magnetic force is described in terms of a constant amount of charge. 𝓆 is moving with a constant speed. 𝑣 In a constant magnetic field, 𝐵. The magnetic field can frequently be calculated based on the distance to a known current, so even if we don’t know the magnetic field strength directly, we can still use this method.
Magnetic Formula
The Lorentz Force is the combination of the magnetic and electric force on a point charge due to electromagnetic fields. Describes the magnetic force: 𝐹 =𝑞𝑣 ×𝐵
The vector cross product is used to write it in this format. Expanding the cross product allows us to express the magnetic force’s magnitude. When a number is negative, its magnitude is converted to its absolute value.
Relation of Magnetic Force to Magnetic Field
The only charges that are affected by the magnetic force are those that are already moving. The magnetic field transmits it. Electric fields and forces are simpler than magnetic fields and forces, which are both more complex.
Magnetic Field
The area in which the force of magnetism acts around a magnetic material or a moving electric charge is known as the magnetic field. The first person to systematically investigate the phenomenon of magnetism using scientific methods was an Englishman named William Gilbert (1540–1603). André-Marie Ampere proposed that whenever an electrical charge is in motion, a magnetic field is created.
Magnetic Field Properties
In the vicinity of a magnet, an electric current, or a shifting electric field, there is a vector field called a magnetic field where magnetic forces can be seen. Electric charges in motion and the intrinsic magnetic moments of elementary particles connected to the fundamental quantum property known as spin create a magnetic field. As parts of the electromagnetic force, one of the four fundamental forces of nature, magnetic field and electric field are interdependent.
Magnetic Field Formula
Tesla is the magnetic field’s SI unit of measurement. The field intensity producing one newton of force per ampere of current per meter of conductor is known as a tesla (1 T).
The magnetic field grows in proportion to the conductor’s increased current. The magnetic field weakens with distance from the wire as we move farther away. This is described by Ampere’s law. The equation gives the magnetic field at a distance r from a long current-carrying conductor I, in accordance with the law.
The permeability of free space (defined in the equation as 0=410-7 T m/A) is a special constant called 0 in the formula.
Higher permeability materials have the capacity to focus magnetic fields.
Since the magnetic field is a vector quantity, it has direction. This can be calculated using the right-hand rule for conventional current flowing through a straight wire. To apply this rule, picture wrapping your right hand around the wire with your thumb pointing in the desired direction. The magnetic field’s path around the wire is indicated by the fingers.
Magnetic Flux
A measurement of the total magnetic field that traverses a specific area is called magnetic flux. It is a helpful tool for explaining how the magnetic force affects something occupying a specific area. The particular area selected will determine how magnetic flux is measured. The region can be any size and oriented in relation to the magnetic field as desired.
The Weber, which bears the symbol Wb and is named after German physicist and co-inventor of the telegraph Wilhelm Weber, is the SI unit of magnetic flux.
Magnetic Flux Properties
The magnetic flux is, if we select a straightforward flat surface with area 𝛢 as our test area and there is an angle between the normal to the surface and a magnetic field vector (magnitude 𝛣).
The angle is zero and the magnetic flux is just when the surface is perpendicular to the field. Figure 1 depicts an illustration of a flat test area exposed to a magnetic field at two different angles and the resulting magnetic flux.
Magnetic Flux Formula
The vector dot product can be used to determine the magnetic flux. If 𝛢, with vector on top, is the surface-normal vector to the test area and 𝛣, with vector on top, is a magnetic field vector, then = 𝛣𝛢.
Electromagnetism
Electromagnetism is a branch of physics that deals with the electromagnetic force that occurs between electrically charged particles. The electromagnetic force is one of the four fundamental forces and exhibits electromagnetic fields such as magnetic fields, electric fields, and light. It is the basic reason electrons are bound to the nucleus and are responsible for the complete structure of the nucleus.
Moreover, electromagnetism is a process where a magnetic field is created by introducing the current in the conductor. When a conductor is electrically charged it generates magnetic lines. For example, if current, i.e., positive charges move in a wire, it produces the magnetic field along the wire, and the direction of magnetic lines and force can be determined using the Right-hand Rule.
Electricity and magnetism are different facets of electromagnetism
a moving electric charge produces magnetic fields
changing magnetic fields move electric charges
This connection first elucidated by Faraday, Maxwell
Einstein saw electricity and magnetism as frame-dependent facets of unified electromagnetic force
Electromagnetic Force
Electromagnetic force also called Lorentz Force discusses the interactions between charged particles in motion and those at rest. Magnetic force and electric forces are actually the same fundamental force, which is why it is termed the electromagnetic force. The electromagnetic force is one of the four fundamental forces. It incorporates the previously distinct electric force and the magnetic force.
The other types are:
Electrostatic force - which builds up charge in an object and can travel in the form of an electron stream
Magnetic force - which is responsible for how the way magnets work
Michael Faraday
Faraday, the greatest experimentalist in electricity and magnetism of the 19th century and one of the greatest experimental physicists of all time, worked on and off for 10 years trying to prove that a magnet could induce electricity. In 1831 he finally succeeded by using two coils of wire wound around opposite sides of a ring of soft iron.
He is probably best known for his discovery of electromagnetic induction, his contributions to electrical engineering and electrochemistry or due to the fact that he was responsible for introducing the concept of field in physics to describe electromagnetic interaction.
Faraday’s Law of Electromagnetic Induction
Faraday’s law of electromagnetic induction, also known as Faraday’s law, is the basic law of electromagnetism which helps us predict how a magnetic field would interact with an electric circuit to produce an electromotive force (EMF). This phenomenon is known as electromagnetic induction.
Faraday’s Laws of Electromagnetic Induction consists of two laws. The first law describes the induction of emf in a conductor and the second law quantifies the emf produced in the conductor. In the next few sections, let us learn these laws in detail.
