7.1.2 Electromagnetism

• What is electromagnetism defined as?

  The interaction between electricity and magnetism
• Fleming's left-hand rule is used to determine the direction of magnetic force on moving charges.


  True
• The source of magnetism in an electromagnet is an electric current.
• What are some common uses of permanent magnets?

  Compasses and refrigerators
• What is the purpose of an iron core in an electromagnet?

  To intensify the magnetic field
• The strength of a permanent magnet can be adjusted.

  False
• When an electric current flows through a wire, it produces a magnetic field around the wire.
• What materials are commonly used in permanent magnets?

  Iron, nickel, cobalt
• Wrapping a wire around an iron core in an electromagnet increases the magnetic field strength.


  True
• When an electric current flows through a wire, it creates a magnetic field around the wire.
• What law describes electromagnetic induction?

  Faraday's law
• A permanent magnet's magnetism can be switched on or off.

  False
• The magnetic field around a wire is stronger if the electric current's magnitude increases.


  True
• A coil of wire called a solenoid enhances the magnetic field.
• What is the source of magnetism in a permanent magnet?

  Internal structure of the material
• Electromagnets have a fixed magnetic strength.

  False
• The strength of the magnetic field around a wire depends on the current's magnitude and the number of turns in the coil.
• Why is an electromagnet's control better than a permanent magnet's?

  It can be switched on/off
• The strength of a permanent magnet is adjustable.

  False
• The strength of a magnetic field created by an electric current depends on the magnitude of the current and the number of turns
• What are two use cases for permanent magnets?

  Compasses, refrigerators
• The magnetic force on a moving charge is perpendicular to its velocity and the magnetic field.


  True
• In the Lorentz force equation, 'q' represents the charge
• What is electromagnetism defined as?

  Interaction between electricity and magnetism
• What two factors determine the strength of the magnetic field produced by an electric current?

  Magnitude and turns
• The magnetic force on a moving charge is described by the Lorentz force equation.
• What are the two states of control for electromagnets?

  On and off
• Electromagnets are used in compasses.

  False
• What equation describes the magnetic force on a moving charge?

  $\vec{F} =$$q(\vec{v} \times \vec{B})$
• For a negative charge, the magnetic force direction is opposite to what the right-hand rule indicates
• Steps for using Fleming's left-hand rule

  1️⃣ Hold your left hand flat

  2️⃣ Point your first finger in the direction of the magnetic field

  3️⃣ Point your middle finger in the direction of the electric current

  4️⃣ Your thumb points in the direction of the magnetic force
• Fleming's left-hand rule is used to determine the direction of the magnetic field.

  False
• Faraday's law of induction states that EMF is proportional to the rate of change of magnetic flux.


  True
• The source of magnetism in an electromagnet is an electric current
• Can an electromagnet be switched off?

  Yes
• Wrapping a wire around an iron core in an electromagnet intensifies the magnetic field.


  True
• What is the Lorentz force equation?

  $\vec{F} =$$q\vec{v} \times \vec{B}$
• The right-hand rule is used to determine the direction of the magnetic force on a moving charge.


  True
• Electromagnets can produce a stronger magnetic field than permanent magnets.


  True
• Steps to determine the magnetic force direction using the right-hand rule

  1️⃣ Point fingers in velocity direction

  2️⃣ Curl fingers towards magnetic field direction

  3️⃣ Thumb points in force direction