10.8 Conservation of Electric Energy

• Electric potential energy is the energy a charge possesses due to its position in an electric field
• Match the force with its associated potential energy:

  Electric ↔️ Electric Potential Energy

  Gravitational ↔️ Gravitational Potential Energy
• Applying force to bring two positive charges closer together increases the system's potential energy.


  True
• Moving a positive charge away from a negatively charged plate increases its electric potential energy.
• Moving a positive charge away from a larger positive charge decreases its electric potential energy.
• Moving a positive charge away from a negatively charged plate increases its electric potential energy.
• What is the electric potential energy of two charges $1 \times 10^{ - 6} C$ and $2 \times 10^{ - 6} C$ separated by 0.5 meters?


  0.36 J
• Match the force with its associated potential energy:

  Electric ↔️ Electric Potential Energy

  Gravitational ↔️ Gravitational Potential Energy
• Calculate the electric potential energy of a $2 \mu C$ charge located 0.5 meters from a $10 \mu C$ fixed charge.


  0.36 J
• The factors that affect electric potential energy are charge, electric field, and distance
• What is the principle of conservation of mechanical energy?

  Total energy remains constant
• Mathematically, what is the relationship between work done and change in electric potential energy?

  $W =$$- \Delta U$
• What does the conservation of energy in electric systems mean?

  Total energy remains constant
• Match the energy type with its formula:

  Kinetic Energy (KE) ↔️ $\frac{1}{2} m v^{2}$

  Electric Potential Energy (U) ↔️ $qV$
• The total energy at the initial state is equal to the total energy at the final state.

  True
• Electric potential energy arises from conservative forces, where the work done moving between two points does not depend on the path
• What three factors affect electric potential energy?

  Charge, field strength, distance
• A $2 \mu C$ charge is 0.5 meters from a fixed $10 \mu C$ charge. What is its electric potential energy in joules?


  $0.36 J$
• What is the mathematical expression for the work done on a charge in terms of electric potential energy?

  $W =$$- \Delta U$
• Steps for analyzing energy transformations in an electric field:

  1️⃣ Calculate initial KE and U

  2️⃣ Calculate final KE and U

  3️⃣ Apply conservation of energy

  4️⃣ Determine energy transformations
• In an electric system, energy can transform between kinetic and potential energy while the total remains constant.


  True
• The formula for electric potential energy is qV
• What is kinetic energy in electric systems?

  Energy due to motion
• The principle of conservation of energy states that initial energy equals final energy.
• In electric fields, the electric force is conservative.


  True
• The work done by a conservative force depends on the path taken.

  False
• Moving a positive charge away from a negatively charged plate increases its electric potential energy.
• What is the electric potential energy of a $2 \mu C$ charge located 0.5 meters from a $10 \mu C$ charge?


  0.36 J
• Match the force with its associated potential energy:

  Electric ↔️ Electric Potential Energy

  Gravitational ↔️ Gravitational Potential Energy
• What is the electric potential energy of a $2 \mu C$ charge located 0.5 meters from a $10 \mu C$ charge?


  0.36 J
• Match the force with its associated potential energy:

  Electric ↔️ Electric Potential Energy

  Gravitational ↔️ Gravitational Potential Energy
• In electric fields, the electric force is conservative.


  True
• Electric potential energy deals with charged particles and electric fields
• Steps in the process of electric potential energy transformation

  1️⃣ Positive charge is placed near a larger positive charge

  2️⃣ Electric potential energy increases

  3️⃣ Charge is moved away from the larger charge

  4️⃣ Electric potential energy decreases

  5️⃣ Potential energy converts to kinetic energy
• Electric potential energy is inversely proportional to the strength of the electric field.

  False
• The total mechanical energy of a system remains constant unless external work is done on it.


  True
• An electron with initial kinetic energy $5 \times 10^{ - 15} J$ moves in an electric field where its potential energy changes from $10 \times 10^{ - 15} J$ to $3 \times 10^{ - 15} J$. What is its final kinetic energy?


  $12 \times 10^{ - 15} J$
• Energy can transform between kinetic energy and electric potential energy, but the total energy remains the same.

  True
• The formula for electric potential energy is qV
• What is electric potential energy?

  Energy due to position