Magnetism and Electromagnetism Flashcards
Magnetic Field
The region around a magnet where magnetic forces can be detected.
Magnetic Flux
The measure of the quantity of magnetism, considering the strength and extent of the magnetic field.
Electromagnet
A type of magnet where the magnetic field is produced by an electric current.
Electromagnetic Induction
The process of generating an electric current from the motion of a conductor through a magnetic field.
Fleming’s Left-Hand Rule
A rule used to predict the direction of the force on a current-carrying conductor in a magnetic field.
Transformers
Devices that change the voltage of an alternating current (AC) supply.
Step-up Transformer
Increases voltage and decreases current.
Step-down Transformer
Decreases voltage and increases current.
How can you increase the strength of an electromagnet?
Increase the current through the coil, increase the number of turns in the coil, or use a core made of soft iron.
Describe how a transformer works and its purpose.
A transformer changes the voltage of an alternating current. It works by electromagnetic induction, with primary and secondary coils wound around a magnetic core. The AC in the primary coil induces a varying magnetic field, which induces a voltage in the secondary coil.
What is the difference between a permanent magnet and an electromagnet?
A permanent magnet produces a constant magnetic field and retains its magnetism, while an electromagnet produces a magnetic field only when an electric current flows through it and can be turned on and off.
Explain the motor effect and how it is used in electric motors.
The motor effect occurs when a current-carrying conductor is placed in a magnetic field, experiencing a force perpendicular to both the field and the current. This principle is used in electric motors to convert electrical energy into mechanical motion.
Why does a moving conductor in a magnetic field induce an electric current?
According to Faraday’s Law of Electromagnetic Induction, a changing magnetic field within a closed loop induces an electromotive force (EMF), causing a current to flow if the circuit is closed.
