Magnetic Forces

Magnetic Forces

Magnetic Field and Magnetic Field Lines

  • A magnetic field is a region where magnetic force can be felt. It exists in the surrounding area of a magnet or a current-carrying wire.
  • The direction of a magnetic field is always from the North pole to the South pole.
  • Magnetic field lines are used to illustrate the strength and direction of a magnetic field. They are always continuous, forming closed loops without starting or ending.
  • The closer the field lines are to each other, the stronger the magnetic field.

Magnetic Forces on Moving Charges

  • Magnetic forces are experienced by moving, charged particles when they are in a magnetic field.
  • The direction of the force is always perpendicular to the direction of the magnetic field and the direction of motion of the charged particle. This is known as Fleming’s left hand rule.
  • The force on the charged particle can be increased by increasing the charge, the speed of the particle, or the strength of the magnetic field.

Magnetic Forces and Current-Carrying Conductors

  • A current-carrying conductor placed in a magnetic field experiences a force. The direction of this force can also be determined using Fleming’s left hand rule.
  • If the current in the conductor is reversed, the direction of the force is also reversed. Same is the case if the direction of the magnetic field is reversed.
  • The magnitude of the force can be increased by increasing the current, the length of the conductor inside the field, or the strength of the magnetic field.

Electromagnetism

  • Current-carrying coils of wire, known as solenoids, produce a strong magnetic field inside the coil. This principle is used in electromagnets.
  • By controlling the amount of electric current, the strength of the magnetic field produced by an electromagnet can be adjusted.

Remember, understanding these fundamental ideas about magnetic forces and fields is essential for comprehending the remaining topics of electricity and magnetism. Keep practising with diagrams and different numerical values to become confident in this section.