Chapter 19 review

    Match each word to the sentence where it best fits.
      Section 19.1

      armature commutator
      electric motor electromagnetism
      electromagnets polarity
      1. When you identify which end of a magnet is north you have determined its _______.
      2. As an electrical device rotates about its axis, the curved plates that create alternating voltages are called the _______.
      3. The subject of _______ connects the flow of electricity to the magnetic force.
      4. _______ can be created by wrapping wires carrying electricity around a metal nail.
      5. When Ravi wrapped a long wire around a cardboard tube he was creating a/an _______.
      6. The part of an electrical device that has rotating electromagnets is the _______.
      7. The _______ converts electrical energy into rotational motion of its axle.
      Section 19.2

      Faraday’s law of induction Lenz’s law
      electrical generator electromagnetic induction
      magnetic flux transformer
      1. A hydroelectric power plant has a/an _______ that converts the rotational motion of the turbines into electricity.
      2. Electricity from a hydroelectric power plant is usually converted to high voltage using a/an _______.
      3. The _______ is a measure of the amount of magnetic field that passes through a closed loop of wire.
      1. Voltage can be created in a conductor by nearby, changing magnetic flux in a process called _______.
      2. That a changing magnetic field through a loop of 10 wire coils will induce more current than the same changing magnetic field through a loop of 3 wire coils is a consequence of ________.
      3. That an induced current flows in the direction to oppose a changing magnetic flux follows from ________.
      Section 19.3

      cathode ray tube (CRT) cyclotron radius
      galvanometer mass spectrometer
      permeability of free space voice coil
      1. The _______ is a scientific instrument that can determine what elements are present in a gas.
      2. An indication of how well a magnetic field can be established in a vacuum is called the ________.
      3. Older kinds of television sets and computer monitors use a _______ to form the picture.
      4. In a bubble chamber image, the _______ can be used to determine the mass and charge of a particle.
      5. A scientific instrument that is a sensitive detector of small electric currents is the _______.
      6. At the heart of a loudspeaker is the _______, which moves up and down in response to changing electric current through it.
      Conceptual questions
        Section 19.1
          Bar magnet near a coil of wire carrying electric current
        1. Easy A coil of wire carries a current as shown in the diagram. Will the bar magnet be attracted or repelled by the coil?

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