Electricity and circuits

• What is the purpose of a battery in a circuit?

  Provides a potential difference
• What does a switch do in an electric circuit?

  Provides a potential difference
• What is the function of an ammeter?

  Allows the current flow to be switched on or off
• What does a voltmeter measure?

  Measures potential difference across a component
• What is the purpose of a fixed resistor?

  Measures the current flowing through a component
• What does a variable resistor do?

  Provides a variable (changeable) resistance
• What is the function of an incandescent lamp?

  Converts electrical energy to light energy
• What does a motor do in a circuit?

  Converts electrical energy to kinetic energy
• What is the function of a diode?

  Allows current to flow in one direction only
• What happens to the resistance of a thermistor when temperature increases?

  Resistance decreases
• What happens to the resistance of an LDR when light intensity increases?

  Resistance decreases
• What is an LED?

  A diode that emits light when current flows
• What are the key differences between series and parallel circuits?

  • Series circuits have one loop; parallel circuits have multiple loops.
  • Current is the same in series; it splits in parallel.
  • Voltage adds up in series; remains the same across branches in parallel.
• What is the definition of electric current?

  Rate of flow of charge
• What is the unit of charge?

  Coulomb (C)
• How is current measured?

  Using an ammeter connected in series
• How do you calculate charge using current and time?

  Q = I × t
• What is the unit of resistance?

  Ohm (Ω)
• What does conventional current flow from?

  From positive to negative in a circuit
• What does Ohm's law state?

  Current is proportional to potential difference
• How does the resistance of a circuit affect the current?

  Higher resistance results in smaller current
• What are the characteristics of resistors in parallel?

  • Current splits among branches.
  • Voltage across each branch is the same.
  • Total current is the sum of currents in branches.
• How do you calculate energy transferred using charge and potential difference?

  E = Q × V
• What are the characteristics of resistors in series?

  • Current through each resistor is the same.
  • Voltages across resistors add up to cell voltage.
  • Total resistance is the sum of individual resistances.
• What is the equation for Ohm's law?

  V = I × R
• If a charge of 25C passes through a motor with a potential difference of 6V, how much energy is transferred?

  150J
• What is the relationship between energy, charge, and potential difference?

  E = Q × V
• How do you calculate the average current if a charge of 1200C flows for 4 minutes?

  I = Q ÷ t
• Why are voltmeters connected in parallel?

  To measure potential difference across components
• What does a steeper line on an I-V graph indicate?

  Lower resistance in the resistor
• What is the total resistance in a series circuit?

  Sum of individual resistances
• How does the arrangement of resistors in parallel affect total resistance?

  It decreases total resistance
• What is the formula to calculate resistance using voltage and current?

  R = V / I
• What does the variable resistor do in a circuit?

  It collects various values for current and voltage
• What does a steeper line on an I-V graph indicate about resistors A and B?

  Resistor A has a lower resistance than B
• What are the characteristics of resistors in series?

  • Current through each resistor is the same
  • Sum of voltages equals cell voltage
• What is the total resistance in the given series circuit?

  12Ω
• If the total potential difference from the battery is 6V and total resistance is 12Ω, what is the current flowing?

  0.5A
• What are the characteristics of resistors in parallel?

  • Total current equals sum of branch currents
  • Potential difference across resistors is equal to battery voltage
• What is the missing potential difference across resistor Y if the total is 12V?

  6V