Electromagnets Basics

Electromagnets

• An electromagnet is a type of magnet that produces a magnetic field when an electric current flows through it.
• Consists of a coil of wire wrapped around a core, typically made of iron or ferrite.
• The magnetic field strength is proportional to the number of turns of the coil, the current flowing through it, and the permeability of the core.
• Electromagnets can be turned on and off by controlling the electric current.
• Applications:
  • Lifting and moving heavy objects in industry
  • Magnetic Resonance Imaging (MRI) machines
  • Electric motors and generators

Magnetic Induction

• Magnetic induction is the process of generating an electric current in a conductor when it is placed in a changing magnetic field.
• Faraday's law of induction: ε = -N(dΦ/dt), where ε is the electromotive force, N is the number of turns of the coil, and dΦ/dt is the rate of change of magnetic flux.
• Lenz's law: the direction of the induced current is such that it opposes the change in the magnetic field.
• Applications:
  • Generators and alternators
  • Transformers
  • Induction cooktops

Magnetic Fields

• A magnetic field is a region around a magnet or electrical current where the magnetic force can be detected.
• Magnetic field lines:
  • Emerges from the north pole and enters the south pole of a magnet
  • Continuous and closed loops
  • Density of lines indicates strength of the magnetic field
• Magnetic field strength (B) is measured in teslas (T) and is proportional to the magnetic field intensity (H) and the permeability of the material.
• Applications:
  • Magnetic Resonance Imaging (MRI) machines
  • Magnetic storage devices (e.g. hard drives)
  • Magnetic separation and sorting in industry

Electromagnets

• Electromagnets produce a magnetic field when an electric current flows through them.
• They consist of a coil of wire wrapped around a core, typically made of iron or ferrite.
• The magnetic field strength is proportional to the number of turns of the coil, the current flowing through it, and the permeability of the core.
• Electromagnets can be turned on and off by controlling the electric current.
• They are used in various applications, such as:
  • Lifting and moving heavy objects in industry
  • Magnetic Resonance Imaging (MRI) machines
  • Electric motors and generators

Magnetic Induction

• Magnetic induction is the process of generating an electric current in a conductor when it is placed in a changing magnetic field.
• Faraday's law of induction states that ε = -N(dΦ/dt), where ε is the electromotive force, N is the number of turns of the coil, and dΦ/dt is the rate of change of magnetic flux.
• Lenz's law states that the direction of the induced current is such that it opposes the change in the magnetic field.
• Applications of magnetic induction include:
  • Generators and alternators
  • Transformers
  • Induction cooktops

Magnetic Fields

• A magnetic field is a region around a magnet or electrical current where the magnetic force can be detected.
• Magnetic field lines emerge from the north pole and enter the south pole of a magnet, and they form continuous and closed loops.
• The density of magnetic field lines indicates the strength of the magnetic field.
• The magnetic field strength (B) is measured in teslas (T) and is proportional to the magnetic field intensity (H) and the permeability of the material.
• Applications of magnetic fields include:
  • Magnetic Resonance Imaging (MRI) machines
  • Magnetic storage devices (e.g., hard drives)
  • Magnetic separation and sorting in industry