Physics P4

    Cards (40)

    • What are the two poles of a magnet called?
      North and South
    • What happens when two like poles of magnets are brought together?
      They repel each other
    • What occurs when two opposite poles of magnets are brought together?
      They attract each other
    • What are permanent magnets?
      Magnets that are always magnetic and always have poles
    • How can induced magnets be created?
      By stroking magnetic materials with a permanent magnet
    • What materials are commonly used to create induced magnets?
      Iron, Nickel, and Cobalt
    • How are magnetic fields represented?
      Using field lines that point from north to south
    • What happens to the strength of a magnetic field as the distance from the magnet increases?
      The strength of the field decreases
    • What does a small plotting compass do in relation to magnetic fields?
      It shows the direction of the magnetic field at a certain point
    • What is the Earth's core described as?
      Magnetic
    • Why does a freely suspended magnetic compass point North?
      Because it aligns itself with the Earth's magnetic field lines
    • Where is the magnetic north pole located?
      Over North Canada
    • Why is the Earth's magnetic pole above Canada considered a magnetic South Pole?
      Because like poles repel each other
    • What does current flowing in a wire produce?
      A magnetic field around the wire
    • What rule dictates the direction of the magnetic field around a wire?
      The right hand grip rule
    • How does the strength of the magnetic field change with the current flowing?
      The greater the current, the stronger the magnetic field
    • What happens to the magnetic field as the distance from the wire increases?
      The magnetic field becomes weaker
    • What is a solenoid?
      A coil of wire with current flowing through it
    • How does coiling the wire in a solenoid affect the magnetic field?
      It enhances the magnetic effect by aligning the field
    • What increases the strength of a solenoid's magnetic field?
      Inserting an iron core in the center
    • What factors can affect the strength of the magnetic field produced by a solenoid?
      • Size of current
      • Length of coil
      • Cross-sectional area
      • Number of turns (coils)
      • Type of core used
    • What type of force do two magnets exert on each other?
      A magnetic force of attraction or repulsion
    • How does the magnetic field around a wire differ from the magnetic field between two magnets?
      The magnetic field around a wire is circular, while between magnets it is straight
    • What does Fleming's Left-Hand Rule help determine?
      The direction of the force on a current-carrying conductor in a magnetic field
    • What is the formula for calculating force in a magnetic field?
      F = BIL
    • What does magnetic flux density measure?
      The number of flux lines per meter squared
    • How does an electric motor operate?
      It rotates a coil of current-carrying wire between fixed permanent magnets
    • What happens to electrons in a conductor when the magnetic field changes?
      They move to one side, creating a potential difference
    • What is generated when a wire cuts through a magnetic field?
      A potential difference
    • What type of current flows when a coil of wire is connected to a complete circuit after being rotated in a magnetic field?
      An alternating current
    • What happens to the magnetic field when alternating current is used?
      The magnetic field constantly changes direction
    • How does a transformer work with alternating current?
      The changing magnetic field induces a current in the secondary coil
    • What happens if the primary current in a transformer is direct?
      Nothing would be induced in the secondary coil
    • What is a step-up transformer?
      A transformer with more turns on the secondary coil
    • What is a step-down transformer?
      A transformer with fewer turns on the secondary coil
    • What is the relationship between the number of coils and the potential difference in a transformer?
      Number of coils on primary / number of coils on secondary = pd of primary / pd of secondary
    • What do dynamic microphones produce?
      A current proportional to the sound signal
    • How does a dynamic microphone work?
      Sound waves cause a coil to move within a magnetic field, inducing a current
    • What happens to the current in a loudspeaker?
      The current flows into the coil, causing it to move and produce sound waves
    • What are the steps involved in how dynamic microphones work?
      1. Sound waves cause pressure variations.
      2. Coil moves within a magnetic field.
      3. Current is induced in the coil.
      4. Current flows to a loudspeaker.
      5. Loudspeaker converts current back to sound waves.
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