What is the principle that describes the force between two charges according to Coulomb's law?

The force is proportional to the product of the charges and inversely proportional to the square of the distance between them.

Fill in the blank: In electrostatics, the electric field intensity E due to a point charge q at a distance r is given by ______.

E = k * q / r²

True or False: The electrostatic force between two charges is a central force.

True.

Riddle: I have a strength that weakens over distance, yet I can affect objects without touching them. What am I?

An electric field.

What is the value of the permittivity of free space in SI units?

Approximately 8.85 x 10⁻¹² F/m.

What defines the electric field due to a charge q at a point in space?

The electric field is defined as the force experienced by a unit test charge placed at that point.

Fill in the blank: The superposition principle states that the total electric field due to multiple charges is the ______ of the electric fields due to each charge.

Vector sum

True or False: The force between two charges becomes zero only when they are infinitely far apart.

True.

What is the relative strength of the electromagnetic force compared to the strong nuclear force?

The electromagnetic force is about 1/137 of the strong nuclear force.

Riddle: I am exchanged between particles to create forces, but I have no mass. What am I?

A photon.

What does the divergence theorem relate in the context of electric fields?

It relates the flux of a vector field through a surface to the divergence of the field within the volume enclosed by the surface.

Fill in the blank: The electric field strength inside a conductor in electrostatic equilibrium is ______.

Zero

True or False: Equipotential surfaces are always perpendicular to electric field lines.

True.

What happens to the electric field inside a dielectric material when an external electric field is applied?

The electric field inside the dielectric is reduced compared to the external field.

Riddle: I can hold charge but I won't let electrons flow freely. What am I?

A dielectric.

What is the effect of a dielectric on the capacitance of a capacitor?

The capacitance increases by a factor equal to the dielectric constant.

Fill in the blank: The potential energy stored in a capacitor is given by ______.

U = 1/2 CV²

True or False: In a uniform electric field, the potential difference between two points is the same regardless of the path taken.

True.

What is the relationship between electric field E and electric displacement D in a dielectric?

D = εE, where ε is the permittivity of the dielectric.

Riddle: I am a path where no work is done when moving along me, and my potential is constant. What am I?

An equipotential surface.

What does the term 'polarization' refer to in the context of dielectrics?

The separation of positive and negative charges within a material in response to an electric field.

Fill in the blank: The concept of a solid angle is defined as the ratio of the area subtended by a surface to the ______.

Square of the distance from the point

True or False: The total electric flux through a closed surface is always zero.

False. It is zero only if there are no charges enclosed.

What is Gauss's law for electric fields?

The electric flux through a closed surface is equal to the charge enclosed divided by ε₀.

Riddle: I can be positive or negative, but when I am zero, I indicate balance. What am I?

Net charge.

What is the significance of the fine structure constant in electrostatics?

It characterizes the strength of the electromagnetic interaction.

What is the principle behind Coulomb's law?

Coulomb's law describes electrical forces.

• Charges attract or repel each other.

• Force depends on charge magnitudes.

• Force decreases with distance squared.

Which of the following forces is the strongest? A) Gravitational force B) Electrostatic force C) Weak nuclear force D) Strong nuclear force

D) Strong nuclear force

Riddle: I’m a central force, my strength decreases as the square of distance, and I act between two charges. What am I?

Electrostatic force

True or False: The electric field inside a conductor in electrostatic equilibrium is non-zero.

False. The electric field inside a conductor in electrostatic equilibrium is zero.

Fill in the blank: The electric field due to a point charge q at a distance r is given by ______.

E = k * q / r²

What is the electric field strength due to an infinitely long line charge with linear charge density λ at a distance r?

E = λ / (2πε₀r)

True or False: The potential energy of a system of charges can be negative.

True. The potential energy can be negative depending on the configuration of the charges.

Which fundamental force is responsible for beta decay?

Weak nuclear force

Riddle: I am the force that keeps protons and neutrons together, but I am not electric. What force am I?

Strong nuclear force

Fill in the blank: The potential at a point in an electric field is defined as the work done per unit charge in bringing a charge from ______ to that point.

Infinity

What is the relationship between electric field (E) and electric potential (V)?

E = -dV/dr

In a dielectric, the polarization vector P is related to the electric field E by what equation?

P = ε₀χE, where χ is the electric susceptibility.

True or False: The force between two point charges is a contact force.

False. The force between two point charges is a non-contact force.

What is the effect of introducing a dielectric material into a capacitor?

The capacitance increases due to the dielectric constant of the material.

Fill in the blank: The energy stored in a capacitor is given by ______.

U = 1/2 CV²