FESci

• What is electricity described as in the study material?

  Universal medium for energy transmission
• What is the charge model in electrostatics?

  • Frictional forces add/remove charge
  • Two kinds of charge: negative (plastic) and positive (glass)
  • Like charges repel, opposite charges attract
  • Force size is proportional to charge and inversely proportional to distance
  • Neutral objects have equal charges
• What is required to transfer charge?

  Contact between objects
• How do conductors and insulators differ in charge mobility?

  Conductors allow free charge movement, insulators do not
• What is the fundamental unit of charge?

  e (elementary charge)
• What happens to molecular bonds when two materials slide past each other?

  Friction breaks molecular bonds at the surface

  
• What does the law of conservation of charge state?

  Charge is neither created nor destroyed
• What is the practical unit of charge?

  1 coulomb
• How do insulators and conductors behave when charged?

  • Insulators: charge remains immobile
  • Conductors: charge moves freely
  • Charging insulators often involves rubbing
  • Conductors respond instantly to charge changes
• What is the effect of charging an insulator by friction?

  Leaves immobile patches of ions on surface
• How do humans discharge a charged object?

  By touching it, allowing charge transfer
• What is charge polarization?

  Separation of positive and negative charges in a neutral object

  
• What is an electric dipole?

  Two opposite charges with slight separation
• How does a charged rod pick up pieces of paper?

  By polarizing atoms in the paper

  
• What does Coulomb's law describe?

  • Force between charged particles
  • Magnitude of force depends on charge and distance
  • Forces are action/reaction pairs
  • Applies to point charges only

  
• What is the first law of electrostatics?

  Like charges repel, unlike charges attract
• What is the second law of electrostatics?

  Force is proportional to product of charges
• What is the relative permittivity of air?

  1
• What is the significance of electric forces being vectors?

  They have both magnitude and direction
• What is the electric field?

  • Long-range force
  • Exists at every point in space
  • Describes interaction between charged particles
  • Force on charge depends on electric field strength

  
• What is the unit of electric field strength?

  N/C (newtons per coulomb)

  
• How does electric potential relate to electric potential energy?

  Electric potential energy is interaction energy of charges
• What is the formula for electric potential energy?

  U = qV

  
• What is the function of a battery in an electric circuit?

  • Source of electric potential
  • Uses chemical reactions to separate charge
  • Creates potential difference between terminals
  • Provides energy to the circuit
• What does emf stand for?

  Electromotive force
• What is Kirchhoff's junction law?

  Total current into junction equals total current out

  
• What are the key components of an electric circuit?

  • Interconnection of electrical elements
  • Includes batteries, resistors, and capacitors
  • Current flows through the circuit
  • Voltage drives the current

  
• What is the definition of current?

  Flow of charge through a conductor

  
• What is Ohm's law?

  Current depends on potential difference and resistance
• What is the unit of current?

  Ampere (A)
• What does resistance depend on?

  Length, diameter, and material of the conductor
• What are the characteristics of series and parallel resistors?

  • Series: same current, total voltage is sum
  • Parallel: same voltage, total current is sum
  • Series resistors have equal charges
  • Parallel resistors have the same potential difference

  
• What is the unit of capacitance?

  Farad (F)
• What is the formula for capacitance of a parallel-plate capacitor?

  C = ε(A/d)
• What is the energy stored in a charged capacitor?

  U = 1/2 CV^2
• What are practical applications of capacitors?

  • Flash units in cameras
  • Defibrillators for medical use
  • Energy storage in various devices
• What happens in an RC circuit?

  Current varies as capacitor charges/discharges
• What is the effect of a switch in an RC circuit?

  Controls the charging and discharging of the capacitor
• What does a battery transfer charge from?

  Bottom electrode to top electrode
• How does the equivalent capacitance of parallel capacitors compare to a single capacitor?

  It is larger than any single capacitor