Electromagnets in devices

• Explain to me how a loudspeaker works:

  1. An alternating current flows through and induces a magnetic field in the coil
  2. The magnetic field of the coil then interacts with the magnetic field of the permanent magnet
  3. This exerts a force on the coil, pushing it back on forth along magnet due to the alternating current
  4. The alternating movement will produce vibrations leading to sound waves

  
• Explain to me how an Electric Bell works:

  1. When switch is closed, circuit is complete so a current flows and induces a magnetic field due to the electromagnet.
  2. The electromagnet attracts the metal arm, causing it to hit the bell. This breaks the circuit.
  3. The Magnetic field fades away and the metal arm returns to its place completing the circuit again, repeating the process