The unit in which charge is measured is the___.
An object is___when it has equal numbers of positive and negative charges.
___exists when there is an excess of one type of charge on an object.
___explains the relationship between electric force, charge, and distance.
____occurs when clothes brush against each other in the dryer.
charging by friction
An____can be used to tell whether an object has a net charge.
If you use a charged balloon to charge a metal ball through ____, the balloon's net charge does not change.
What does it mean to say an object is electrically neutral?
An object is electrically neutral when its net charge is zero.
How does the charge of an electron compare to the charge of a proton?
The charge of an electron is equal to the charge of a proton with the opposite sign.
Why don't you usually notice electric forces between objects?
Because most objects are electrically neutral.
What two factors determine the amount of electric force between two objects?
the size of the charges and the distance between the charges
What happens to the force between two charges as they are moved closer together?
The force between the charges gets stronger.
Explain what happens to the force between two protons if each of the following occurs: The distance between them is cut in half.
force increases by four times
Explain what happens to the force between two protons if each of the following occurs: The distance between is doubled.
the force decreases by four times
Explain what happens to the force between two protons if each of the following occurs: The distance between them is tripled.
the force decreases by nine times
Explain what happens to the force between two protons if each of the following occurs: One of the protons is replaced with an electron.
the force becomes attractive
Explain what happens to the force between two protons if each of the following occurs:One of the protons is replaced with two electrons.
force is attractive and increases by two times
What happens to the charges in your hair and a balloon if you rub them together?
hair will become positively charged; balloon will become negatively charged
___is when you rub a balloon on your hair.
charging by friction
___are drawn to show the direction of the electric field.
an object is____if has a net positive charge on one side and a net negative charge on the other side.
There is an____in the region around any charge.
How are the units ampere and coulomb related?
amperes are coulombs per second
Ben Franklin defined current as going from ______. Now we know that electrons in a circuit move from ___.
positive to negative; negative to positive
Do all the electrons in a wire move to make the current in a circuit?
no, only the valence electrons move
Does a battery supply the electrons to a circuit that create current in a circuit?
Why can current easily be created in a conductor but not in an insulator?
Because conductors have electrons that are free to move and insulators do not.
One volt equals one ___of energy per __of charge. A volt is also equal to one ____of power per___of current.
joule, coulomb; watt, ampere
A___is used to store electrical energy by separating charge.
Capacitance is measured in__.
What is a capacitor?
A capacitor is a device that stores electrical energy in a circuit.
What use do capacitors have?
A charged capacitor can create current in a circuit.
What does it mean to say a capacitor is charged?
A capacitor is charged when one plate is positively charged and the other is negatively charged.
What happens to the current in a circuit as a capacitor charges?
The current in a circuit containing a capacitor decreases to zero as the capacitor charges.
Which three factors affect a capacitor's capacitance?
the distance between the plates; the area of the plates; the insulating material between the plates
How much charge does a 8.85 farad capacitor hold when charged with a 12 volt battery?
Find the net charge of an atom that contains each of the following. 4 protons and 14 electrons
How many protons are needed to make 2.4 coulomb of charge?
How many electrons are in a coulomb?
What is the formula for current? Voltage?