AP Physics 2 Flashcards: Conservation Of Electric Energy

What this deck covers

This deck focuses on Conservation Of Electric Energy, giving you a quick way to review the definitions, rules, and examples that matter most for AP Physics 2.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Calculate the work done if a charge $q = 5C$ moves through $\Delta V = 3V$.

Answer: $W = 15 \text{ J}$. Using $W = q\Delta V = 5 \times 3 = 15$ J.

Flashcard 2: What is the relationship between electric potential and potential energy?

Answer: $U = qV$. Potential energy equals charge times electric potential.

Flashcard 3: What is the potential energy of a charge in a field with zero potential difference?

Answer: Zero. No potential difference means no stored energy.

Flashcard 4: Identify the formula for converting potential difference to electric field strength.

Answer: $E = -\frac{\Delta V}{d}$. Relationship between field strength and potential gradient.

Flashcard 5: What does the symbol $k_e$ represent in electric potential formulas?

Answer: Coulomb's constant. Fundamental constant in Coulomb's law and electric formulas.

Flashcard 6: Which factor does not affect electric potential energy in a uniform field?

Answer: The direction of $d$. Direction doesn't affect energy magnitude in uniform fields.

Flashcard 7: Identify the relationship between electric field strength and potential difference.

Answer: $E = -\frac{\Delta V}{d}$. Electric field is negative gradient of potential.

Flashcard 8: State the principle of conservation of electric energy.

Answer: Total electric energy remains constant in an isolated system. Fundamental principle: energy cannot be created or destroyed.

Flashcard 9: Define the term 'electric potential'.

Answer: Work done per unit charge to move a charge from infinity. Potential is work per unit charge from reference point.

Flashcard 10: What is the unit of electric potential in the SI system?

Answer: Volt (V). Standard SI unit for electric potential difference.

Flashcard 11: What is the formula for the work done by an electric field?

Answer: $W = qEd$. Work equals force times distance in uniform field.

Flashcard 12: Identify the effect on potential energy if distance increases in a point charge field.

Answer: Decreases. Potential energy varies as $1/r$ for point charges.

Flashcard 13: State how electric potential energy changes when moving against the field.

Answer: Increases. Moving against field requires work, increasing energy.

Flashcard 14: How does electric potential vary with distance from a point charge?

Answer: Inversely proportional. Potential follows inverse square law like electric field.

Flashcard 15: State what happens to potential energy when a charge moves with the field.

Answer: Decreases. Field does positive work, reducing potential energy.

Flashcard 16: What is the effect on potential energy if a charge is halved?

Answer: Halves. Energy is directly proportional to charge.

Flashcard 17: What is the potential energy of a 2C charge at a potential of 5V?

Answer: $U = 10 \text{ J}$. Using $U = qV = 2 \times 5 = 10$ J.

Flashcard 18: Identify the unit of electric potential energy in the SI system.

Answer: Joule (J). Standard SI unit for energy in all forms including electric.

Flashcard 19: Calculate the electric potential energy for $q = 3C$ and $V = 4V$.

Answer: $U = 12 \text{ J}$. Using $U = qV = 3 \times 4 = 12$ J.

Flashcard 20: Calculate the electric potential energy for $q = 4C$ and $V = 6V$.

Answer: $U = 24 \text{ J}$. Using $U = qV = 4 \times 6 = 24$ J.

Flashcard 21: State how electric potential energy changes when moving against the field.

Answer: Increases. Moving against field requires work, increasing energy.

Flashcard 22: State the formula for electric potential due to a point charge.

Answer: $V = k_e \frac{q}{r}$. Potential created by point charge $q$ at distance $r$.

Flashcard 23: Calculate the electric potential energy for $q = 3C$ and $V = 4V$.

Answer: $U = 12 \text{ J}$. Using $U = qV = 3 \times 4 = 12$ J.

Flashcard 24: What does the conservation of electric energy imply for potential changes?

Answer: Sum of changes is zero. Net energy change is zero in conservative systems.

Flashcard 25: Calculate the potential energy change for $q = 1C$ and $\Delta V = -2V$.

Answer: $\Delta U = -2 \text{ J}$. Using $\Delta U = q\Delta V = 1 \times (-2) = -2$ J.

Flashcard 26: Calculate the electric potential energy for $q = 4C$ and $V = 6V$.

Answer: $U = 24 \text{ J}$. Using $U = qV = 4 \times 6 = 24$ J.

Flashcard 27: What is the effect of increasing charge on electric potential energy?

Answer: It increases linearly. Potential energy is directly proportional to charge.

Flashcard 28: What is the change in potential energy if a charge is moved to a lower potential?

Answer: Decreases. Lower potential means reduced stored energy.

Flashcard 29: Which factor does not affect electric potential energy in a uniform field?

Answer: The direction of $d$. Direction doesn't affect energy magnitude in uniform fields.

Flashcard 30: Identify the relationship between work done and electric potential energy.

Answer: $W = -\Delta U$. Work done equals negative change in potential energy.

Flashcard 31: Identify the unit of electric potential energy in the SI system.

Answer: Joule (J). Standard SI unit for energy in all forms including electric.

Flashcard 32: Find the change in electric potential energy if $q = 2C$ and $\Delta V = 5V$.

Answer: $\Delta U = 10 \text{ J}$. Using $\Delta U = q\Delta V = 2 \times 5 = 10$ J.

Flashcard 33: What happens to electric potential energy if charge is doubled?

Answer: It doubles. Energy is directly proportional to charge magnitude.

Flashcard 34: Calculate the work done if a charge $q = 5C$ moves through $\Delta V = 3V$.

Answer: $W = 15 \text{ J}$. Using $W = q\Delta V = 5 \times 3 = 15$ J.

Flashcard 35: What is the unit of Coulomb's constant $k_e$?

Answer: $\text{N} \cdot \text{m}^2/\text{C}^2$. Units derived from Coulomb's law force equation.

Flashcard 36: What is the formula for electric potential energy?

Answer: $U = qV$. Energy stored in charge $q$ at electric potential $V$.

Flashcard 37: Which physical quantity is conserved in an isolated electric system?

Answer: Electric energy. Total electric energy remains constant in isolated systems.

Flashcard 38: Find the change in electric potential energy if $q = 2C$ and $\Delta V = 5V$.

Answer: $\Delta U = 10 \text{ J}$. Using $\Delta U = q\Delta V = 2 \times 5 = 10$ J.

Flashcard 39: What does the symbol $k_e$ represent in electric potential formulas?

Answer: Coulomb's constant. Fundamental constant in Coulomb's law and electric formulas.

Flashcard 40: Identify what must be true for electric energy conservation in a circuit.

Answer: Closed circuit, no external work. Requirements for energy conservation in electrical systems.

Flashcard 41: What is the unit of electric potential in the SI system?

Answer: Volt (V). Standard SI unit for electric potential difference.

Flashcard 42: Identify the effect on potential energy if distance increases in a point charge field.

Answer: Decreases. Potential energy varies as $1/r$ for point charges.

Flashcard 43: What quantity does the symbol $U$ represent in electric energy equations?

Answer: Electric potential energy. Standard symbol for electric potential energy in physics.

Flashcard 44: Identify the formula for converting potential difference to electric field strength.

Answer: $E = -\frac{\Delta V}{d}$. Relationship between field strength and potential gradient.

Flashcard 45: What happens to electric potential energy if charge is doubled?

Answer: It doubles. Energy is directly proportional to charge magnitude.

Flashcard 46: What is the unit of Coulomb's constant $k_e$?

Answer: $\text{N} \cdot \text{m}^2/\text{C}^2$. Units derived from Coulomb's law force equation.

Flashcard 47: What is the potential energy of a 2C charge at a potential of 5V?

Answer: $U = 10 \text{ J}$. Using $U = qV = 2 \times 5 = 10$ J.

Flashcard 48: What is the change in potential energy if a charge is moved to a lower potential?

Answer: Decreases. Lower potential means reduced stored energy.

Flashcard 49: Calculate the potential energy change for $q = 1C$ and $\Delta V = -2V$.

Answer: $\Delta U = -2 \text{ J}$. Using $\Delta U = q\Delta V = 1 \times (-2) = -2$ J.

Flashcard 50: State the formula for electric potential due to a point charge.

Answer: $V = k_e \frac{q}{r}$. Potential created by point charge $q$ at distance $r$.

Flashcard 51: What is the effect on potential energy if a charge is halved?

Answer: Halves. Energy is directly proportional to charge.

Flashcard 52: What does the conservation of electric energy imply for potential changes?

Answer: Sum of changes is zero. Net energy change is zero in conservative systems.

Flashcard 53: What is the formula for the work done by an electric field?

Answer: $W = qEd$. Work equals force times distance in uniform field.

Flashcard 54: State the expression for the electric potential difference in a uniform field.

Answer: $\Delta V = Ed$. Potential difference in uniform field over distance $d$.

Flashcard 55: State what happens to potential energy when a charge moves with the field.

Answer: Decreases. Field does positive work, reducing potential energy.

Flashcard 56: State the formula for electric potential energy in a uniform electric field.

Answer: $U = qEd$. Energy stored in charge within uniform electric field.

Flashcard 57: How does electric potential energy change with distance in a uniform field?

Answer: Decreases with distance. Energy decreases as charge moves with field direction.

Flashcard 58: State the formula for electric potential energy in a uniform electric field.

Answer: $U = qEd$. Energy stored in charge within uniform electric field.

Flashcard 59: How does electric potential vary with distance from a point charge?

Answer: Inversely proportional. Potential follows inverse square law like electric field.

Flashcard 60: Identify the relationship between work done and electric potential energy.

Answer: $W = -\Delta U$. Work done equals negative change in potential energy.

Flashcard 61: Identify the relationship between electric field strength and potential difference.

Answer: $E = -\frac{\Delta V}{d}$. Electric field is negative gradient of potential.

Flashcard 62: State the principle of conservation of electric energy.

Answer: Total electric energy remains constant in an isolated system. Fundamental principle: energy cannot be created or destroyed.

Flashcard 63: Calculate the potential energy for $q = 3C$ and $V = -2V$.

Answer: $U = -6 \text{ J}$. Using $U = qV = 3 \times (-2) = -6$ J.

Flashcard 64: What is the effect of increasing charge on electric potential energy?

Answer: It increases linearly. Potential energy is directly proportional to charge.

Flashcard 65: What is the potential energy of a charge in a field with zero potential difference?

Answer: Zero. No potential difference means no stored energy.

Flashcard 66: What quantity does the symbol $U$ represent in electric energy equations?

Answer: Electric potential energy. Standard symbol for electric potential energy in physics.

Flashcard 67: Define the term 'electric potential'.

Answer: Work done per unit charge to move a charge from infinity. Potential is work per unit charge from reference point.

Flashcard 68: Which physical quantity is conserved in an isolated electric system?

Answer: Electric energy. Total electric energy remains constant in isolated systems.

Flashcard 69: Calculate the potential energy for $q = 3C$ and $V = -2V$.

Answer: $U = -6 \text{ J}$. Using $U = qV = 3 \times (-2) = -6$ J.

Flashcard 70: How does electric potential energy change with distance in a uniform field?

Answer: Decreases with distance. Energy decreases as charge moves with field direction.

Flashcard 71: What is the formula for the potential energy of a dipole in an electric field?

Answer: $U = -pE \cos \theta$. Energy depends on dipole moment and field alignment.

Flashcard 72: Identify what must be true for electric energy conservation in a circuit.

Answer: Closed circuit, no external work. Requirements for energy conservation in electrical systems.

Flashcard 73: State the expression for the electric potential difference in a uniform field.

Answer: $\Delta V = Ed$. Potential difference in uniform field over distance $d$.

Flashcard 74: What is the relationship between electric potential and potential energy?

Answer: $U = qV$. Potential energy equals charge times electric potential.