magnetism

• What is a transformer used for?

  To change the voltage of alternating current
• What principle does a transformer operate on?

  Electromagnetic induction
• What are the two coils in a transformer called?

  Primary and secondary coils
• What role does the iron core play in a transformer?

  Enhances the magnetic field and provides a path
• How is the primary coil connected in a transformer?

  To the input voltage (mains electricity)
• How does an AC in the primary coil affect the secondary coil?

  It generates a changing magnetic field
• What happens if the secondary coil has more turns than the primary coil?

  It is a step-up transformer
• What is the output voltage of a step-down transformer?

  Lower than the input voltage
• What does an ideal transformer conserve?

  Power, meaning input equals output
• Why are step-up transformers used at power stations?

  To increase voltage for efficient transmission
• What must happen to electricity before it enters homes?

  It must be stepped down to a safer level
• What are the main reasons transformers are not 100% efficient?

  Heat loss due to coil resistance
• How can the efficiency of transformers be improved?

  Using low-resistance coils and laminated cores
• What are the key components and functions of a transformer?

  • Two coils: primary and secondary
  • Iron core enhances magnetic field
  • Changes voltage of alternating current
  • Step-up or step-down based on coil turns
• What do generators convert into electrical energy?

  Mechanical energy
• What are the applications of transformers in everyday life?

  • Used in national grid for power transmission
  • Step-up transformers increase voltage at power stations
  • Step-down transformers reduce voltage for home use
• How does a generator induce current in a wire?

  By moving a conductor through a magnetic field
• What can increase the size of the induced current in a generator?

  Moving the wire more rapidly
• What does Fleming’s Right Hand Rule demonstrate in generators?

  How to determine the direction of induced current
• What is another name for a simple AC generator?

  Dynamo
• What does a simple AC generator consist of?

  A coil rotating in a magnetic field
• What happens to the direction of current in a generator as the coil rotates?

  It alternates as the coil rotates
• How do commercial generators differ from simple generators?

  They use multiple coils and slip rings
• What principle do microphones use to convert sound waves?

  Magnetism
• What are the main components of a typical microphone?

  Diaphragm, coil of wire, permanent magnet
• What happens when sound waves strike the diaphragm of a microphone?

  It causes the diaphragm to vibrate
• How does the vibration of the diaphragm affect the induced current?

  Louder sounds induce a larger current
• How does the frequency of the induced current relate to sound pitch?

  Higher pitches induce a higher frequency current
• What can be done to the electrical signal from a microphone?

  It can be amplified and sent to a speaker
• What is the process of electromagnetic induction in generators?

  • Mechanical energy is converted to electrical energy
  • A conductor moves through a magnetic field
  • Induced current is generated in the conductor
• What are the differences between simple and commercial generators?

  Simple Generators:

  • Use a single coil
  • Employ split ring commutators

  
  

  Commercial Generators:

  • Use multiple coils
  • Utilize slip rings for smoother AC
• How do microphones convert sound into electrical signals?

  • Sound waves vibrate the diaphragm
  • Diaphragm movement induces current in the coil
  • Current size corresponds to sound loudness
  • Current frequency corresponds to sound pitch
• What is the generator effect?

  Production of voltage due to motion
• How does the generator effect differ from the motor effect?

  The generator effect produces voltage, motor effect uses it
• What does Faraday’s Law of Electromagnetic Induction state?

  Induced voltage is proportional to magnetic field change rate
• What does Lenz’s Law state about induced current?

  Induced current opposes the change in magnetic field
• How can the magnitude of induced voltage be increased?

  By moving the conductor faster or using a stronger magnetic field
• What does Fleming’s right-hand rule help determine?

  The direction of induced current in a generator
• What is the role of the armature in a generator?

  It rotates in a magnetic field to induce current
• How does a generator produce alternating current (AC)?

  By alternating the direction of induced current every half-turn