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Transformers quiz

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  • Which of the following statements about transformers is correct?
    Transformers use electromagnetic induction to adjust the voltage of electricity, based on Faraday's law. The voltage transformation ratio is determined by the ratio of the number of turns in the output coil to the input coil. For example, to reduce 120 volts to 15 volts using a coil with 50 turns, the second coil should have approximately 6.25 turns for the most efficient setup.
  • What is the primary function of a transformer in an electrical circuit?
    A transformer adjusts the voltage of electricity using electromagnetic induction, based on Faraday's law.
  • How does a transformer use Faraday's law to function?
    A transformer uses a changing magnetic field in one coil to induce an electromotive force (EMF) in another coil.
  • What determines the voltage transformation ratio in a transformer?
    The voltage transformation ratio is determined by the ratio of the number of turns in the output coil to the input coil.
  • Why is it necessary to reduce the voltage from power stations before it reaches homes?
    The voltage generated at power stations is too high for household appliances, so it must be reduced to a safer level, like 120 volts in North America.
  • What is the relationship between the input and output voltages in a transformer?
    The ratio of the output voltage to the input voltage equals the ratio of the number of turns in the output solenoid to the input solenoid.
  • In the example given, how many turns are needed for the second solenoid to reduce 120 volts to 15 volts?
    The second solenoid needs approximately 6.25 turns if the first solenoid with 50 turns is the output solenoid.
  • What happens if the 50-turn solenoid is used as the input solenoid instead of the output solenoid?
    If the 50-turn solenoid is the input solenoid, the second solenoid would need 400 turns, which is not the most efficient setup.
  • What is the significance of the number of turns in the solenoids of a transformer?
    The number of turns in the solenoids determines the voltage transformation ratio, affecting how much the voltage is increased or decreased.
  • Why is it important to choose the solenoid configuration that requires the fewest turns for the second solenoid?
    Choosing the configuration with the fewest turns for the second solenoid minimizes material use and construction complexity, making the transformer more efficient.