Unit 6 Summative Assessment: Electrostatic Field

What are the SI units of the permittivity of free space ε₀?

Two point charges placed in vacuum attract each other with force F. When placed at the same distance in a liquid medium of relative permittivity εᵣ = 5.0, what is the new electrostatic force?

Calculate the electrostatic repulsive force in Newtons between two point charges of +2.0 μC and +5.0 μC separated by 30.0 cm in vacuum. Take 1/(4πε₀) = 8.99 × 10⁹ N m² C⁻².

How is the electric field intensity E at a point in an electric field formally defined?

Calculate the magnitude of the electric field in kN C⁻¹ (or kV m⁻¹) at a distance of 50 cm from a point charge of +4.0 μC in vacuum. Take 1/(4πε₀) = 8.99 × 10⁹ N m² C⁻².

How is the electric potential V at a point in an electrostatic field defined?

Calculate the electric potential in kiloVolts (kV) at a distance of 30.0 cm from a point charge of +6.0 μC in vacuum. Take 1/(4πε₀) = 8.99 × 10⁹ N m² C⁻².

What is the mathematical relationship between electric field strength E and electric potential V in a one-dimensional field?

How much work is done by the electric field when moving a test charge q along an equipotential surface?

An alpha particle (charge q = +2e = 3.20 × 10⁻¹⁹ C) is accelerated from rest through a potential difference of 50.0 kV. Calculate its final kinetic energy in femtojoules (fJ, 10⁻¹⁵ J).

What is the statement of Gauss’s Law for electrostatics in vacuum?

A point charge of +8.854 nC is placed at the center of a cubical Gaussian surface of side 10 cm. Calculate the total electric flux emerging through the entire cube in N m² C⁻¹ (or V m). Take ε₀ = 8.854 × 10⁻¹² F m⁻¹.

What is the electric flux through one single face of a cube if a point charge Q is placed at the exact geometric center of the cube?

Where does excess charge reside on a solid or hollow conducting body in electrostatic equilibrium?

A solid conducting sphere of radius 10.0 cm holds a net charge of +5.0 μC in vacuum. What is the electric field strength in kN C⁻¹ at a distance of 5.0 cm from the center of the sphere?

How is the electrical capacitance C of any conductor or capacitor defined?

A parallel-plate capacitor with air between the plates has plate area 200 cm² and plate separation 1.0 mm. Calculate its capacitance in picofarads (pF). Take ε₀ = 8.854 × 10⁻¹² F m⁻¹.

A parallel plate capacitor is charged by a battery and then DISCONNECTED from the battery. A slab of dielectric material (εᵣ = 4.0) is subsequently inserted between the plates. How do the stored charge Q, capacitance C, and potential difference V change?

Which of the following expressions does NOT represent the electrostatic energy U stored in a charged capacitor?

A 50.0 μF capacitor is charged to a potential difference of 200 V. Calculate the energy stored in the capacitor in Joules.