Electrostatics (chapt 22)
An electron is pushed into an electric field where it acquires a 1-V electrical potential. If two electrons are pushed the same distance into the same electric field, the electrical potential of the two electrons is
1 V
Assume that 10 J of work is need to pusha charge, at rest, into an electric field. After the charge is released there, it flies back to its starting position and its kinetic energy there will be
10 J
Two charges separated by one meter exert 1-N forces on each other. If the magnitude of each charge is doubled, the force on each charge is
4 N
If you use 10 J of work to push a coulomb of charge into an electric field, its voltage with respect to its starting position is
10 V
Two charges separated by one meter extert 1-N forces on each other. If the charges are pushed to 1/4 meter separation, the force on each charge will be
16 N
Superconductors are noted for their
absence of electric resistance.
An electron and a proton
attract each other
The direction of an electric field is the direction of the force that the field would exert on
a proton
The unit of electric charge, the coulomb, is the charge on
a specific large number of electrons
An uncharged pith ball is suspended by a nylon fiber. When a negatively charged rubber rod is brought nearby, without touching it, the pith ball
becomes polarized
Electric potential, measured in volts, is the ration of electrical energy to amount of electric
charge
Normally a small party balloon charged to several thousand volts will have a relatively small amount of
charge and energy
The electrical force between charges is strongest when the charges are
close together
The primary purpose of a lightning rod is to
discharge the structure to which it is attached
A balloon will stick to a wooden wall if the balloon is charged
either positively or negatively
The electric field inside the dome of a Van de Graaff generator (OPTIONS: (a) depends on the amount of charge outside of dome (b) depends on the volume of the dome (c) both a and b are correct (d) none of the above
none of the above choices are correct
A positive charge and a negative charge held near each other are released. As they move, the force on each particle
increases
Charge carrieres in a metal are electrons rather than protons because electrons are
loosely bound
The electricla force between charges depends only on the charges'
magnitude and separation distance
If you comb your hair and the comb becomes positively charged, then your hair becomes
negatively charged
To say that electric charge is conserved means that no case has ever been found where the
net charge has been created or destroyed
A difference between electric forces and gravitational forces are nto affected by
repulsive interaction
Two protons attract each other gravitationally and repel each other electrically. By far the greater force is
the electrical repulsion
Particle A has twice the charge of nearby particle B. Compared to the force on Particle A, the force on Particle B is
the same
Two charged particles held near each other are released. As they move, the acceleration of each decreases. Therefore, the particles have
the same sign
Two charges separated by one meter exert 1-N forces on each other. If the charges are pulled to 3-m separation distance, the force on each charge will be
0.11 N
The electrical force on a 2-C charge is 60 N. What is the value of the electric field at the place where the charge is located?
30 N/C
When a single charge q is placed on one corner of a square, the electric field at the center of the square is F/q. If two other equal charges are placed at the adjacent corners of the square, the electric field at the center of the square due to these three equal charges is
F/q
Every proton in the universe is surrounded by its own
electric field and gravitational field
The fundamental force underlying all chemical reactions is
electrical
Which force binds atoms together to form molecules?
electrical
A proton and an electron are placed in an electric field. Which undergoes the greater acceleration?
electron
You can touch a 100,000-volt Van de Graaff generator with little harm because although the voltage is high, the relatively small amount of charge means there is a relatively small amount of
energy
An electroscope is charged positively as shown by foil leaves that stand apart. As a negative charge is brought close to the electroscope, the leaves
fall closer together
When a single charge q is placed on one corner of a square, the electric field at the center of the square is F/q. If three other equal charges are placed on the other corners, the electric field at the center of the square due to these four equal charges is
none of the above choices are correct
A conductor differs from an insulator in that a conductor
none of these
Strip electrons from an atom and the atom becomes a
positive ion
A negatively charged rod is held near a metal can that rests on a dry wood table. If you touch the opposite side of the can momentarily with your finger, the can is then
positively charged
After a capacitor is fully charged, the total number of electrons it contains
remains unchanged
A main difference between gravitational and electric forces is that electrical forces
repel or attract
In the unlikely case of a lightning strike, it is worse to be inside a builiding framed with
wood
The electric field inside an uncharged metal ball is zero. If the ball is negatively charged, the electric field inside the ball is then
zero
When a car is struck by lightning, the resulting electric field inside the car is
zero
