P1 electricity

• What are the three main components that make up an atom?

  Electrons, protons, and neutrons
• Where are neutrons and protons located in an atom?

  In the nucleus of the atom
• Where are electrons located in an atom?

  Surrounding the nucleus in shells
• What are the two types of charged particles in an atom?

  Protons and electrons
• What is the charge of a proton?

  +1
• What is the charge of an electron?

  -1
• Which side of a cell symbol represents the positive terminal?

  Left
• How does a thermistor's resistance change with temperature?

  Resistance decreases as temperature increases
• What is another name for voltage?

  Potential difference
• What are the differences between series and parallel circuits regarding current?

  Same current flows in series, varies in parallel
• What are the differences between series and parallel circuits regarding voltage?

  Voltage is shared in series, same in parallel
• Where must a voltmeter be placed in a circuit?

  In parallel with the component being measured
• What is the equation relating potential difference with energy transferred and charge?

  Voltage (V) = energy transferred (J) / charge (C)
• How can a volt be described in terms of energy and charge?

  Joule per coulomb
• What is an electric current?

  The rate of flow of charge
• What is an ammeter and where must it be connected?

  An ammeter measures current, placed in series
• What equation can be used to measure charge including time and current?

  Charge (C) = Time (s) x Current (A)
• In a closed circuit, if there is a potential difference, what else will there be?

  Current
• State the equation linking current, voltage, and resistance with their units.

  Voltage (V) = Current (A) x Resistance (Ω)
• How does changing the resistance in a circuit affect the current?

  Increasing resistance decreases current at constant voltage
• What is the equation linking current, voltage, and resistance?

  V = I x R
• What happens to current when resistance increases in a circuit?

  • Current is inversely proportional to resistance
  • Higher resistance makes it harder for electrons to flow
  • Therefore, current decreases
• How can you increase the current in a series circuit using a variable resistor?

  Set the variable resistor to lower resistance
• Why does the overall resistance increase when two resistors are in series?

  Overall resistance is the sum of individual resistances
• Explain the relationship between current and voltage in series resistors.

  • Current is the same through each resistor: I1 = I2 = IT
  • Total voltage is the sum of voltages across each resistor: VT = V1 + V2
  • Therefore, RT = R1 + R2
• Why does the net resistance of two resistors in parallel decrease?

  Net current is the sum of individual currents
• Describe the relationship between voltage, current, and resistance in a filament lamp.

  • Resistance increases with temperature
  • Higher temperature causes more ion vibration
  • This makes it harder for electrons to pass, decreasing current
  • A filament lamp is non-ohmic
• How do diodes function in a circuit?

  Diodes allow current to flow in one direction only
• What happens to the resistance of a thermistor with temperature changes?

  Resistance decreases as temperature increases
• How does a light-dependent resistor (LDR) work?

  Resistance decreases as light intensity increases

  
• What electrical component does a diode represent?


  Diode
• Why does a resistor heat up when an electrical current flows through it?

  Electrons collide with ions, transferring energy
• How do low resistance wires reduce unwanted energy transfers?

  Fewer collisions lead to less energy wasted
• What are the advantages and disadvantages of the heating effect in electrical components?

  Advantages:

  • Useful in appliances like toasters

  Disadvantages:

  • Energy loss can reduce efficiency
  • Overheating can cause fires or damage
• What is the equation linking electrical energy transferred, voltage, current, and time?

  E = I x V x T
• What is the term for energy transferred per second?

  Power (in Watts)
• What is the equation linking electrical power, current, and voltage?

  P = I x V
• What is the equation for power in terms of current and resistance?

  P = I² x R
• How can you derive the equation for power in terms of current and resistance?

  • Start with P = IV
  • Substitute V = IR into P = IV
  • Resulting equation: P = I² x R
• What is the energy transferred per second also known as?

  Power (in Watts)