Physics (electric charge flow)

    Cards (21)

    • What is the unit used for smaller currents in electrical circuits?
      Milliampere (mA)
    • How many milliamperes are in one ampere?

      1000 mA
    • What is the smallest unit of current mentioned in the material?
      Microampere (µA)
    • How is a current of 1 ampere defined in terms of charge?

      A current of 1 ampere flows when 1 coulomb of charge passes a point in a circuit in 1 second.
    • If a current of 5A is flowing in a circuit, how much charge passes a point in 1 second?

      5C of charge passes every point in 1 second.
    • What is the formula to calculate the charge passing a point in a circuit?

      Q = I x t
    • What do the symbols Q, I, and t represent in the charge formula?

      • Q: Charge (coulombs)
      • I: Current (amperes)
      • t: Time (seconds)
    • If a current of 150 mA flows for 1 minute, how much electrical charge flows past a point in the circuit?

      9C of charge flows past the point.
    • How do you convert 30 µA to milliamperes (mA)?

      30 µA = 0.03 mA
    • How do you convert 50,000 µA to milliamperes (mA)?

      50,000 µA = 50 mA
    • How do you convert 1,000,000 µA to amperes (A)?

      1,000,000 µA = 1 A
    • What is the current in amperes if 400 mA is converted?

      0.4 A
    • What is the charge delivered if a current of 6A flows for 10 seconds?

      60C of charge is delivered.
    • What is the charge delivered if a current of 300 mA flows for 1 minute?

      18C of charge is delivered.
    • How do you calculate the current when a charge of 100C passes in 5 seconds?

      Current = Qt=\frac{Q}{t} =100C5s= \frac{100C}{5s} =20A 20A
    • What happens to the energy in a circuit when it passes through a light bulb?

      • The charge deposits energy in the light bulb
      • The energy is converted to light and heat
    • What happens to the energy in a circuit when it passes through a motor?

      • The motor uses energy to create movement
      • The energy is also converted to heat
    • How is voltage measured in a circuit?

      Using a voltmeter placed in parallel across the component.
    • What is the electromotive force (EMF) of a cell?

      The highest potential difference when the cell is not supplying current.
    • Why does the potential difference drop when a current is being supplied by a cell?

      Due to energy wastage inside the cell.
    • If a car battery is labelled 12V, what might it deliver when used to turn a starter motor?

      It may only deliver 10V when in use.
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