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Electric Fields in Capacitors quiz

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  • What is a capacitor composed of?
    A capacitor is composed of two parallel plates with equal and opposite charges.
  • In which direction does the electric field inside a capacitor point?
    The electric field inside a capacitor points from the positively charged plate to the negatively charged plate.
  • How is the electric field between the plates of a capacitor described?
    The electric field between the plates is uniform, meaning it has the same magnitude at all points between the plates.
  • What is the formula for the electric field inside a parallel plate capacitor?
    The formula is E = Q / (ε₀ × A), where Q is the charge, ε₀ is the vacuum permittivity, and A is the area of each plate.
  • What is the value of the vacuum permittivity (ε₀)?
    The value of ε₀ is 8.85 × 10⁻¹² (in SI units).
  • How are Coulomb's constant (k) and vacuum permittivity (ε₀) related?
    They are related by the equation k = 1 / (4π × ε₀).
  • What is the electric field outside the plates of a capacitor?
    The electric field outside the plates is zero.
  • How do you calculate the charge on each plate given the electric field and area?
    Use Q = ε₀ × A × E, where E is the electric field and A is the area of the plate.
  • Why must you be careful when converting area units from cm² to m²?
    Because you must apply the conversion factor for centimeters to meters twice due to the squared units.
  • If the area of a plate is 5 cm², what is it in m²?
    5 cm² is equal to 5 × 10⁻⁴ m².
  • What is the charge on each plate if E = 1000 N/C and A = 5 cm²?
    The charge is approximately 4.43 × 10⁻⁹ Coulombs.
  • What does it mean for the electric field in a capacitor to be 'uniform'?
    It means the electric field has the same magnitude and direction at every point between the plates.
  • What happens to the electric field lines from the positive and negative plates?
    The field lines from the positive plate point outward and those from the negative plate point inward, resulting in a uniform field between the plates.
  • What is the significance of the charges on the two plates of a capacitor?
    The plates have equal and opposite charges, which is essential for creating the uniform electric field.
  • What is stored between the plates of a capacitor?
    Charge and energy are stored between the plates of a capacitor.