10.3 Electric Permittivity

• Electric permittivity is represented by the Greek letter ε
• The relationship between electric field, flux, and permittivity is given by the equation Φ = ε⋅E, where ε = ε₀⋅εᵣ. What does ε₀ represent?Vacuum
• What happens to the electric force between two charges when the permittivity of the medium increases?

  Decreases
• Two charges of +10 μC and -10 μC are 0.1 m apart in air. Calculate the electric force between them using Coulomb's Law.

  ≈-90 N
• What does electric permittivity quantify in electrostatics?

  Reduces electric field strength
• What is electric permittivity a measure of?

  Electric field transmission ability
• Relative permittivity is a dimensionless quantity.

  True
• The relative permittivity of air is approximately 1.0006
• Relative permittivity is the ratio of the permittivity of a material to the vacuum
• The electric force between two charges is inversely proportional to the permittivity of the medium.

  True
• Order the materials from lowest to highest relative permittivity:

  1️⃣ Vacuum

  2️⃣ Air

  3️⃣ Water
• The relative permittivity of vacuum is equal to 1.


  True
• Match the material with its relative permittivity:

  Vacuum ↔️ 1

  Air ↔️ ≈1.0006

  Water ↔️ ≈78
• What happens to the electric force between two charges when they are moved from vacuum to water?

  It decreases significantly
• Higher permittivity reduces electric force between charges.


  True
• The relative permittivity of vacuum is 1.


  True
• The relationship between electric field, electric flux, and electric permittivity is Φ = ε⋅E.


  True
• Higher permittivity decreases the electric force between charges.


  True
• The permittivity of free space is denoted by ε₀.
• What is the relative permittivity of water?

  ≈78
• What is the primary role of the permittivity of free space (ε₀)?

  Permit electric field lines
• Materials reduce the electric force between charges compared to vacuum.


  True
• What is the permittivity of vacuum?

  8.854 × 10⁻¹² F/m
• What does the relative permittivity (εᵣ) represent in the permittivity formula?

  Ratio to vacuum permittivity
• Match the effect of permittivity with its consequence:

  Higher permittivity ↔️ Decreased electric force

  Lower permittivity ↔️ Increased electric force
• What is the approximate relative permittivity of water?

  78
• What is the relative permittivity of air?

  ≈1.0006
• What effect does higher permittivity have on electric force?

  Reduces electric force
• The permittivity of vacuum is 8.854 × 10⁻¹² F/m.
• The electric force is lower in water due to its higher permittivity.
• The permittivity of free space is a constant value equal to 8.854 × 10⁻¹² F/m.
• Electric permittivity is a measure of a material's ability to transmit an electric field.
• Permittivity quantifies the ability of a material to reduce the electric field's strength.
• In Coulomb's Law, the electric force is inversely proportional to the permittivity.
• What is the permittivity of free space (ε₀)?

  8.854 × 10⁻¹² F/m
• The electric force between two +5 μC charges 0.1 m apart in vacuum is approximately 22.4 N
• The permittivity of a material (ε) is expressed as ε₀ × εᵣ
• How does higher permittivity affect electric field strength?

  Reduces it
• The electric force between two charges in water is lower than in vacuum due to water's higher permittivity.


  True
• Order the materials from highest to lowest relative permittivity:

  1️⃣ Water

  2️⃣ Air

  3️⃣ Vacuum