Electric Potential Energy and Electric Potential
Consider two point charges, A and B, separated by a distance, d. How would we find the total electric potential energy of this arrangement?
Calculate one electric potential energy for the pair.
Consider three point charges, A, B, and C, arranged in an equilateral triangle, with distance d on each side. How would we find the total electric potential energy of this arrangement?
Calculate one electric potential energy for the pair. Find the three electric potential energies (one for each pair) and add them up.
How are electric field lines related to equipotential surfaces?
Electric field lines are always perpendicular to equipotential surfaces and point toward locations of lower potential.
Which of these is a good description of the difference between electric potential energy and electric potential?
Electric potential energy is a property of a system of multiple charges while electric potential is a property of a location in space near a charge distribution
Which of these is a good description of the difference between electric potential energy and electric potential?
Electric potential energy is a property of a system of multiple charges while electric potential is a property of a location in space near a charge distribution.
If there is a system with a proton and an electron, can the electric potential energy of the system be exactly zero?
No, it will be negative no matter how they are arranged
If there is a system with two electrons, can the electric potential energy of the system be exactly zero?
No, it will be positive no matter how they are arranged
Which of the following is a good description of the electric force between stationary charged objects?
The electric force between stationary charged objects is a conservative force for which there is a corresponding potential energy.
If an electron is moved a certain distance directly opposite an external electric field, what can we say about the change in the electric potential energy of the system?
The electric potential energy of the system will decrease
If a proton is moved a certain distance directly opposite an external electric field, what can we say about the change in the electric potential energy of the system?
The electric potential energy of the system will increase.
An arbitrarily shaped piece of conductor is given a net negative charge and is alone in space. What can we say about the electric potential within the conductor? Assume that the electric potential is zero at points that are very far away from the conductor.
The electric potential in the conductor will be negative and constant throughout the conductor.
An arbitrarily shaped piece of conductor is given a net positive charge and is alone in space. What can we say about the electric potential within the conductor? Assume that the electric potential is zero at points that are very far away from the conductor.
The electric potential in the conductor will be positive and constant throughout the conductor.
If a proton is moved a certain distance directly opposite an external electric field, what can we say about the change in the electric potential it experiences?
The electric potential it experiences will increase.
If an electron is moved a certain distance directly opposite an external electric field, what can we say about the change in the electric potential it experiences?
The electric potential it experiences will increase.
If an object with charge _2nC moves from a location that has a potential of 20V to a location with a potential of -10V, what has hapened to the potential energy of the system?
The potential energy of the system has decreased by (delta UorV)=-(30V)(2nC)
If an object with charge -3 nC moves from a location that has a potential of -20 V to a location with a potential of -10 V, what has happened to the potential energy of the system?
The potential energy of the system has decreased by delta U is equal to negative 10 V times 3 times n times C.
A cube of copper and a sphere of aluminum are both positively charged and connected by a wire. What do the two conductors have in common?
They both have the same electric potential.
When two electrons are 1 cm apart, what expression could represent their electric potential energy?
U= (1/4piEnaught)([abs val of qe^2/.01m)
Consider a point 1 cm away from an electron with nothing else nearby. What expression could represent the electric potential at that location?
V=-(1/4piEnaught)(absval of qe/.01m)
If there is a system with two electrons and a proton, can the electric potential energy of the system be exactly zero?
Yes, it could be zero if they were arranged properly.
If a composite object is electrically neutral, that means it _______.
can be made from objects that each have zero electrical charge, or made from charged objects with equal amounts of total positive and negative charge
Every point on an equipotential surface ______.
has the same electric potential
If an electron is moved in a direction perpendicular to an equipotential surface,
it will be moving either in the same or exactly opposite direction as the electric field at that location
One similarity between protons and electrons is ______
protons and electrons have the same amount of charge, but protons have positive charge, while electrons have negative charge
When an electron approaches a positively charged nucleus,
the electric potential energy of the system decreases while the potential at the electron's location increases
As we consider various points that are all on the same equipotential surface near some distribution of charge,
the electric potential is the same at every point
As we consider various points that are all on the same equipotential surface near some distribution of charge, ______.
the electric potential is the same at every point, but the electric potential energy is different at every point
If an electron moves in a direction perpendicular to an equipotential surface, ______.
the potential it experiences must change