Electromagnets

• How can you differentiate between magnetic material and a magnet?


  Only the magnet will repel like poles.
• How can you increase the current in a circuit?


  By increasing the voltage applied to it.
• What is the equation for a neutralisation reaction?


  Acid + Alkali → Salt + water
• If Voltage = Current X Resistance, what is the current in a circuit with 12V and a resistance of 4Ω?


  The current is 3A.
• What is the formula to calculate current in a circuit?

  I = V/R
• What are the major organelles observed in Elodea and cheek cells?


  • Chloroplasts
  • Cell wall
  • Vacuole
  • Nucleus
  • Cytoplasm
• Why might the number of chloroplasts observed in Elodea cells vary?


  Due to differences in light exposure and environmental conditions.
• Why might the appearance of chloroplasts vary from cell to cell?


  Due to differences in age or health of the cells.
• What is the function of the cell wall in a plant cell?


  It provides structure and support to the cell.
• What is the purpose of the vacuole in plant cells?


  It stores nutrients and waste products.
• How does a plant cell differ from an animal cell?

  A plant cell has a cell wall and chloroplasts, while an animal cell does not.
• How does the observed movement relate to the cytoplasm in the cell?


  The movement is due to the flow of cytoplasm within the cell.
• Compare and contrast Elodea cells and cheek cells in terms of cell structure and presence of organelles.


  • Elodea cells:
  • Have a cell wall
  • Contain chloroplasts
  • Larger vacuoles
  • Cheek cells:
  • No cell wall
  • No chloroplasts
  • Smaller vacuoles
• What are the ends of a magnet called?


  The ends of a magnet are called poles.
• What is an alloy?


  An alloy is a mixture of two or more elements where one is a metal.
• What are three ways to increase the strength of an electromagnet?


  1. Increase the current flowing through the wire.
  2. Increase the number of coils in the wire.
  3. Use a ferromagnetic core.
• How is an electromagnet formed?


  An electromagnet is formed by a current passing through a wire.
• What happens when a current flows through a coiled wire (solenoid)?


  A magnetic field is produced.
• How does the direction of current affect the magnetic field's direction?

  • Upward current: magnetic field circulates in a counter-clockwise direction
  • Downward current: magnetic field circulates in a clockwise direction
• What does the green arrow represent?

  Current
• What physical phenomenon is shown surrounding the wire?

  Magnetic field
• How is an electromagnet created using a wire and an iron core?

  • Electrical current flows through the wire
  • Magnetic field is generated around the wire
  • Wire is wrapped into a coil (solenoid)
  • Iron core is placed inside the coil
  • Magnetic field is strengthened, creating a temporary magnet
• What are the three essential parts of an electromagnet?

  Iron core, coil of wire, power source
• If the battery is connected to the nail and coil of wire, what type of device is this?

  An electromagnet
• What is the main component of the device shown in the image?

  Battery
• How does wrapping a wire into a coil affect the magnetic field?

  It concentrates and strengthens the magnetic field
• What is the purpose of the coil of wire in the device?

  To create a magnetic field
• What is the function of the iron core in an electromagnet?

  Provides a path for magnetic lines of force
• What happens to the magnetism of an electromagnet when the current stops flowing?

  The magnetism disappears
• How does the structure of an electromagnet differ from a permanent magnet?

  An electromagnet requires electric current to function
• What is an electromagnet?

  A temporary magnet created by electric current
• What is the function of the power source in an electromagnet?

  Provides electric current
• What shape does the magnetic field around the wire take?

  Concentric circles
• What creates a magnetic field around a wire?

  Electrical current flowing through the wire
• What is the purpose of the coiled wire in the simple electromagnet?

  To create a magnetic field
• What is the usual metal core used in electromagnets?

  Iron
• What are the two sides of a magnet called?

  North (N) and South (S)
• What is a temporary magnet?

  Magnetic only when electricity flows
• What is the function of the battery in the simple electromagnet?

  To provide electrical power
• What happens to the iron core when current is flowing through the coil?

  It creates a temporary magnet