Electrostatic Potential and Capacitance Flashcards
What is the notion of potential energy?
The notion of potential energy is introduced as the energy stored when an external force does work against forces like spring force or gravitational force to move a body from one point to another.
What are conservative forces, and what are examples of such forces mentioned?
Conservative forces are forces where the sum of kinetic and potential energies is conserved. Examples include spring force, gravitational force, and Coulomb force between stationary charges.
How is the electrostatic potential energy of a charge defined in an electrostatic field?
Electrostatic potential energy of a charge in an electrostatic field is defined similarly to gravitational potential energy, considering the work done by external forces in moving the charge against the electrostatic force.
Describe the process of bringing a test charge from point R to point P against the repulsive force due to charge Q.
The test charge is brought from point R to point P against the repulsive force due to charge Q by applying an external force equal and opposite to the electric force, ensuring no net force or acceleration on the charge during the process.
What is the relationship between the work done by external forces and the potential energy of a charge?
The work done by external forces in moving a charge against electrostatic repulsive force gets stored as potential energy of the charge.
Explain the concept of potential energy difference in terms of work done.
Potential energy difference between two points is defined as the work required by an external force to move the charge between those points without acceleration, against the electrostatic force.
What are the two important comments made regarding potential energy in the given context?
(i) The work done by an electrostatic field in moving a charge is path-independent, demonstrating the conservative nature of the force. (ii) The actual value of potential energy is arbitrary, but the difference in potential energy between two points is physically meaningful.
How is the potential energy of a charge defined at any point in the presence of an electric field?
The potential energy of a charge at any point in the presence of an electric field is defined as the work done by external forces in bringing the charge from infinity to that point, with the choice of zero potential energy at infinity.
