the motor effect

• According to the introduction, what should you be able to do by the end of the video?

  Describe the motor effect
• What else should you be able to do by the end of this video?

  Calculate the force generated by the motor effect
• What is the final thing the video aims to enable you to do?

  Determine the force direction using Fleming's left-hand rule
• Is the content of this video for high-tier students only, or all students?

  High-tier students only
• What does a previous video mentioned have to say about what happens when a current moves through a wire?

  A magnetic field is produced
• If a wire carrying a current is placed in another magnetic field, what will happen?

  The wire will experience a force
• When a wire carrying an electric current is placed within a magnetic field, what happens?

  The magnetic fields interact
• What do scientists call the phenomenon of a wire experiencing a force when placed in a magnetic field?

  The motor effect
• What formula is used to calculate the size of the force in the motor effect?

  $Force =$$Magnetic flux density *$$Current *$$Length$
• In what units is force measured in the equation for the motor effect?

  Newtons
• In what units is magnetic flux density measured in the equation for the motor effect?

  Tesla
• In what units is current measured in the equation for the motor effect?

  Amperes
• In what units is the length of the wire measured in the equation for the motor effect?

  Meters
• Is the equation for calculating the force in the motor effect provided in the exam?

  Yes
• What angle should the wire be at in relation to the magnetic field for the motor effect equation to apply?

  Right angles
• What does the magnetic flux density measure?

  The strength of the magnetic field
• A wire of 2.5 meters carries a current of 1.5 Amperes in a magnetic flux density of 0.05 Tesla; what is the force on the wire?

  0.19 Newtons
• What three factors affect the size of the force in the motor effect?

  • Magnetic flux density
  • Current
  • Length of the conductor
• What rule is used to determine the direction of the force in the motor effect?

  Fleming's left hand rule
• According to Fleming's left-hand rule, which direction should your first finger point?

  Direction of the magnetic field
• According to Fleming's left-hand rule, which direction should your second finger point?

  Direction of the conventional current
• According to Fleming's left-hand rule, what direction does your thumb point?

  The direction of motion/force
• In Fleming's left-hand rule, from where to where does the magnetic field run?

  North to south
• If the magnetic field runs from left to right and the current flows upwards, what is the direction of motion?

  Out of the page
• According to the video, what happens if the conductor is parallel to the magnetic field?

  It will not experience a force
• When does a conductor experience a force in a magnetic field?

  When it is at right angles
• For which tier of students is the description of how a moving coil loudspeaker or headphones work intended?

  Higher-tier students only
• What effect describes the force experienced by a current-carrying conductor in a magnetic field?

  The motor effect
• In what device, other than loudspeakers and headphones, is the motor effect used?

  The electric motor
• What component is found in loudspeakers that also exists in a smaller version in headphones?

  A moving coil loudspeaker
• What is wrapped around one end of the cone in a moving coil loudspeaker?

  A coil of wire
• To what is the coil of wire connected in a moving coil loudspeaker?

  An AC electrical supply
• What happens when current passes through the coil in a moving coil loudspeaker?

  It generates a magnetic field
• What type of magnet is positioned inside the coil of wire in a moving coil loudspeaker?

  A permanent magnet
• What interacts with the magnetic field from the permanent magnet?

  The coil's magnetic field
• What do the interacting magnetic fields from the coil and the permanent magnet cause?

  A resultant force
• What does the resultant force cause the cone to do in a moving coil loudspeaker?

  Move back and forth
• How are sound waves generated by the cone in a moving coil loudspeaker?

  By moving in and out
• How can the frequency of the cone's vibrations be changed?

  By changing the AC supply frequency
• What happens to the sound produced when the frequency of the cone increases?

  The pitch becomes higher