Charge, current & time

• What is the definition of charge?

  Charge is a measure of total current over time
• How can charge be compared to water flow?

  Charge is the total amount of water flowed
• What symbol represents charge?

  The letter q
• In what unit is charge measured?

  Coulombs
• What is the equation for charge?

  Charge = Current × Time
• If a kettle draws 12 amps for 50 seconds, how much charge passes through?

  600 coulombs
• How do you find the current if charge is 43.2 kilo coulombs over 2 hours?

  Rearrange to i = q / t
• How do you convert kilo coulombs to coulombs?

  Multiply by 1000
• How do you convert hours to seconds?

  Multiply hours by 3600
• What is the current if 43,200 coulombs are transferred in 7,200 seconds?

  6 amps
• What is the relationship between charge, current, and time?

  • Charge (q) = Current (i) × Time (t)
  • Current is measured in amps (A)
  • Time is measured in seconds (s)
• How do you calculate charge in a circuit?

  1. Identify current in amps (A)
  2. Identify time in seconds (s)
  3. Use the formula: q = i × t
• How do you calculate current from charge and time?

  1. Identify charge in coulombs (C)
  2. Identify time in seconds (s)
  3. Rearrange the formula: i = q / t
• What are the unit conversions needed for charge and time?

  • 1 kilo coulomb = 1000 coulombs
  • 1 hour = 3600 seconds