energy resources, electric circuit , equations

• What is a battery?

  A number of electrical cells in series
• What is charge in physics?

  A conserved property of some particles
• What does charge cause particles to do?

  Exert a force on each other
• What is a component in an electric circuit?

  A part of something, like a lamp
• What is a diode?

  A non-ohmic conductor with directional resistance
• How does a diode behave in reverse direction?

  It has much higher resistance
• What does discharge mean in electrical terms?

  To remove an electric charge by conduction
• What does it mean to be earthed?

  Connected to earth for charge flow
• What does a charged object create around itself?

  An electric field
• What are electrons?

  Tiny negatively charged particles
• What does induce mean in physics?

  To create a current in a wire
• What is an ion?

  A charged atom
• What is a light-dependent resistor (LDR)?

  A resistor whose resistance depends on light intensity
• What is a light-emitting diode (LED)?

  A diode that emits light when it conducts
• What are neutrons?

  Uncharged particles in the nucleus
• What is the unit for measuring electrical resistance?

  Ohm (Ω)
• What does it mean for components to be in parallel?

  Potential difference is the same across each
• What is potential difference?

  Work done per coulomb of charge
• What is the unit of potential difference?

  Volt (V)
• What is resistance?

  Difficulty for electricity to flow through
• What is Ohm's law?

  Resistance = potential difference / current
• What happens when you reverse the potential difference across a resistor?

  The current direction also reverses
• How does the resistance of a filament lamp change with temperature?

  Resistance increases as temperature increases
• How does current through a diode depend on potential difference?

  Current flows only in one direction
• What happens to the resistance of a temperature-dependent resistor as temperature increases?

  Resistance decreases as temperature increases
• What happens to the resistance of a light-dependent resistor as light level increases?

  Resistance decreases as light level increases
• What are the characteristics of components in a series circuit?

  • Same current passes through all components
  • Potential difference is divided among components
  • Total resistance is the sum of individual resistances
• What is the potential difference of several cells in series?

  It adds up to the total potential difference
• How do you calculate the total resistance of two resistors in series?

  Add their resistances together
• Why does adding resistors in series increase total resistance?

  It adds to the overall opposition to current
• What are the characteristics of components in a parallel circuit?

  • Potential difference is the same across all components
  • Total current is the sum of individual currents
  • Total resistance is less than the smallest individual resistor
• How do you calculate the current through a resistor in a parallel circuit?

  Use Ohm's law for each branch
• Why is the total resistance of two resistors in parallel less than the smaller resistor?

  Current has multiple paths to flow through
• Why does adding resistors in parallel decrease total resistance?

  It provides more pathways for current flow
• How is static electricity produced?

  • By rubbing surfaces together
  • Transfer of electrons between objects
  • Results in unbalanced electric charges
• What evidence shows charged objects exert forces on each other?

  They attract or repel without contact
• How does the transfer of electrons explain static electricity?

  It creates unbalanced charges on surfaces
• What does the electric field for an isolated charged sphere look like?

  It radiates outward from the sphere
• What is the concept of an electric field?

  Region around a charged object affecting others
• How does the electric field explain non-contact forces?

  It shows how charges interact at a distance