summary
● Laws of electrostatic charges: Like charges repel; unlike charges attract.
● Electrical charge (Q) is measured in coulombs (C).
● One coulomb is equal to 6.24 3 1018 electrons.
● An electric current is the slow drift of electrons from an area of negative charge to an area of positive charge.
● Current flow is measured in amperes.
● One ampere (A) is the amount of current that flows in a conductor when 1 coulomb of charge moves past a point in 1 second.
● The relationship among current, electrical charge, and time is represented by the formula:
● Electrons (negative charge) represent the charge carrier in an electrical circuit.
● Hole movement (positive charge) occurs in the opposite direction to electron movement.
● Current flow in a circuit is from negative to positive.
● Electrons travel very slowly through a conductor, but individual electrons move at the speed of light.
● Scientific notation expresses a very large or small number as a numeral from 1 to 9 to a power of 10.
● If the power-of-10 exponent is positive, the decimal point is moved to the right.
● If the power-of-10 exponent is negative, the decimal point is moved to the left.
● The prefix milli– means one-thousandth.
● The prefix micro– means one-millionth.