Physics Final Review: Charge, Electric Force, Field, and Potential Energy

What is charge by contact?

It occurs when one charged object comes into contact with a neutral object, transferring electrons and resulting in both objects having the same electric potential.

What happens during charge by induction?

A charged object is brought close to a neutral conductor without direct contact, causing a redistribution of charges within the conductor.

What is the role of grounding in charge induction?

Grounding allows electrons to flow to or from the conductor, depending on whether the charged object is positive (sources electrons) or negative (sinks electrons).

What is polarization in the context of electric charge?

Polarization is the separation of positive and negative charges within a neutral object due to the influence of a nearby charged object.

What is the formula for electric force between two charges?

F = k (|q1 q2| / r²), where k = 9.0 × 10⁹ N·m²/C², q1 and q2 are the charges, and r is the separation distance.

How does the electric force change with distance?

The electric force decreases with the square of the distance; if the distance doubles, the force becomes one-fourth.

What is the direction of electric field lines for positive and negative charges?

Electric field lines point outward from positive charges and inward toward negative charges.

What is the formula for electric field strength?

E = k * (Q / r²), where E is the electric field strength, Q is the source charge, and r is the distance from the charge.

What is electric potential energy?

Electric potential energy is the stored energy of two charges held at a distance, represented as U = k (q1 q2 / r).

What is the relationship between electric potential and energy?

Electric potential (V) is related to energy (U) by the formula U = qV, where q is the charge.

How do positive and negative charges move in an electric field?

Positive charges move from high to low potential, while negative charges move from low to high potential.

What does the inverse square law state about electric fields?

The strength of an electric field decreases with the square of the distance from the charge; if the distance doubles, the field strength becomes one-fourth.

What is the significance of the conservation of energy in electric systems?

The conservation of energy states that the total energy (potential and kinetic) remains constant in an isolated system.

What is the formula for calculating work done in an electric field?

W = ΔU, where W is work done, and ΔU is the change in electric potential energy.

What is the electric potential at a distance from a point charge?

V = k * (Q / r), where V is the electric potential, Q is the charge, and r is the distance from the charge.

How do you calculate the net force on a charge placed in an electric field?

The net force can be calculated using F = qE, where F is the force, q is the charge, and E is the electric field strength.

What happens to charges when grounding is removed?

Once grounding is removed, the charges that left cannot return, resulting in a net charge on the conductor.

What is the effect of charge magnitude on electric force?

The electric force is proportional to the product of the magnitudes of the charges involved.

What is the significance of electric field lines in representing electric fields?

Electric field lines visually represent the direction and strength of the electric field, with denser lines indicating stronger fields.

What is the relationship between electric potential and distance in a uniform field?

In a uniform electric field, the potential drops linearly across the distance.

How do you find the force on a charge placed in an electric field?

The force on a charge can be found using F = qE, where q is the charge and E is the electric field strength.

What is the electric potential energy of two charges placed at a distance?

The electric potential energy can be calculated using U = k (q1 q2 / r), where q1 and q2 are the charges and r is the distance between them.

What is the effect of similar and opposite charges on potential energy?

Opposite charges result in negative potential energy (U < 0), while similar charges result in positive potential energy (U > 0).