Electric Potential Flashcards
What is electric potential?
Electric potential is potential energy per unit charge
It represents how much energy a charge has based on its position in an electric field.
What is the electric potential at infinity?
The electric potential at infinity is zero
This is because all points in an electric field have an electric potential, which approaches zero as the distance increases.
How does electric potential vary with distance from a point charge?
Electric potential decreases as the distance from the charge increases
In a radial field, the potential is greatest at the surface of the charge.
What determines the sign of electric potential V?
The sign of V depends on the charge Q
V is positive when Q is positive (force is repulsive) and negative when Q is negative (force is attractive).
What is the electric potential energy for a unit positive charge at a certain point?
Electric potential energy is the electric potential multiplied by the value of the charge
This indicates how much energy a charge has at that point in the electric field.
What is the formula for capacitance C of an isolated charged sphere?
C = 4πε₀R
Here, R is the radius of the sphere and ε₀ is the permittivity of free space.
Fill in the blank: Electric potential is the electric potential energy that a unit positive charge (+1 C) would have at a certain point, which can be calculated by _______.
multiplying the electric potential by the value of the charge
True or False: The absolute magnitude of electric potential V is greatest on the surface of the charge.
True
As the distance from the charge increases, the potential decreases.
What is the unit of capacitance?
The unit for capacitance is farads
Capacitance measures a capacitor’s ability to store charge per unit potential difference.
What relationship exists between electric potential V and charge Q in a radial electric field?
Q = CV
This formula relates charge to capacitance and electric potential in the context of electric fields.
What happens to electric potential V as distance r increases towards infinity for a negative charge?
V is initially negative and tends to zero
This behavior is similar to that of a positive charge in terms of potential approaching zero.
What is gravitational field strength, g?
Force per unit mass
This concept is fundamental in understanding how masses interact in a gravitational field.
What does Newton’s law of gravitation describe?
The force between two point masses as an inverse square law
This law indicates that the force decreases with the square of the distance between the masses.
What is gravitational potential, V?
Potential energy per unit mass, zero at infinity
Gravitational potential helps in calculating the energy required to move a mass in a gravitational field.
What is electric field strength, E?
Force per unit positive charge
This concept parallels gravitational field strength but applies to electric charges.
What does Coulomb’s law describe?
The electric force between two point charges as an inverse square law
Similar to Newton’s law of gravitation, it shows the relationship between force and distance for electric charges.
What is electric potential, V?
Potential energy per unit positive charge, zero at infinity
Electric potential indicates the work done to move a charge in an electric field.
What are the three main differences between gravitational and electric fields?
1) Gravitational forces are always attractive
2) Electric forces can be either attractive or repulsive
3) Objects can be shielded from electric fields, but not from gravitational fields
These differences highlight the unique properties of electric and gravitational interactions.
True or False: Gravitational forces can be either attractive or repulsive.
False
Gravitational forces are always attractive.
Fill in the blank: The size of an electric force depends on the _______.
[medium between the charges]
Examples include different materials like plastic or air that can affect the electric force.
