7.1.1 Magnetism

• What is the definition of magnetism?

  Magnetism is a physical phenomenon produced by the motion of electric charge, resulting in attractive and repulsive forces between objects.
• How is magnetism related to electricity?

  Magnetism is closely related to electricity and is one of the fundamental forces in nature.
• What is a magnetic field?

  A magnetic field is the region around a magnet where magnetic forces can be felt.
• How are the strength and direction of a magnetic field represented?

  The strength and direction of a magnetic field are represented by field lines.
• From which pole do magnetic field lines emerge?

  Magnetic field lines emerge from the north pole of a magnet.
• What does the density of magnetic field lines indicate?

  The density of the lines indicates the strength of the magnetic field; closer lines mean a stronger field.
• What shape do the field lines form for a bar magnet?

  For a bar magnet, the field lines form closed loops from the north pole to the south pole outside the magnet and within the magnet.
• What are the two poles of a magnet called?

  Every magnet has a north pole and a south pole.
• What happens when like poles of magnets are brought together?

  Like poles repel each other.
• What occurs when a magnet is broken?

  If you break a magnet, each piece will become a smaller magnet with its own north and south poles.
• What are ferromagnetic materials?

  Ferromagnetic materials, such as iron, cobalt, and nickel, can be magnetized and are attracted to magnets.
• What happens to the domains in ferromagnetic materials when they are magnetized?

  Domains in ferromagnetic materials align when magnetized.
• What are non-magnetic materials?

  Non-magnetic materials, like wood and plastic, do not respond to magnetic fields.
• What is the difference between permanent and temporary magnets?

  Permanent magnets maintain their magnetic properties over time, while temporary magnets exhibit magnetic properties only when exposed to a magnetic field.
• What is an electromagnet?

  An electromagnet is a type of magnet created by passing an electric current through a coil of wire.
• What enhances the magnetic field of an electromagnet?

  Placing a ferromagnetic material, like iron, inside the coil enhances the magnetic field.
• What is one application of electromagnets?

  Electromagnets are used to operate electric bells.
• How does a magnetic crane utilize electromagnets?

  Magnetic cranes use electromagnets to lift and move ferrous materials.
• What force does a magnetic field exert on a moving electric charge?

  A magnetic field exerts a force on a moving electric charge, and the direction of the force is given by the right-hand rule.
• How can the force on a current-carrying wire in a magnetic field be calculated?

  The force can be calculated using the formula $F =$$B \times I \times L$.
• What does Faraday's Law state?

  Faraday's Law states that a changing magnetic field within a closed loop induces an electromotive force (EMF) in the loop.
• What does Lenz's Law describe?

  Lenz's Law states that the direction of the induced EMF opposes the change in magnetic flux that produced it.
• What is one application of electromagnetic induction?

  Electromagnetic induction is used in transformers and electric generators.
• How do electric motors work?

  Electric motors convert electrical energy into mechanical energy using the interaction between a magnetic field and current-carrying coils.
• What is the function of generators?

  Generators convert mechanical energy into electrical energy using electromagnetic induction.
• What do transformers do?

  Transformers change the voltage of alternating current (AC) by using electromagnetic induction.
• How does Magnetic Resonance Imaging (MRI) work?

  MRI uses strong magnetic fields and radio waves to create detailed images of the inside of the body.
• What are some common experiments to visualize magnetic fields?

  • Sprinkling iron filings on paper placed over a magnet to visualize magnetic field lines.
  • Using a magnetic field sensor or compass to measure and map the strength and direction of magnetic fields.
• What is the summary of magnetism?

  • Magnetism involves the interaction of magnetic fields, magnetic materials, and electric currents.
  • Understanding magnetic fields, poles, and forces is essential for grasping how electromagnets and electric motors work.
  • Applications of magnetism include technological devices, medical imaging, and various industrial processes.