Conservation of Electric Energy - AP Physics 2
Card 1 of 30
Calculate the electric potential energy for $q = 4C$ and $V = 6V$.
Calculate the electric potential energy for $q = 4C$ and $V = 6V$.
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$U = 24 \text{ J}$. Using $U = qV = 4 \times 6 = 24$ J.
$U = 24 \text{ J}$. Using $U = qV = 4 \times 6 = 24$ J.
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What is the formula for the work done by an electric field?
What is the formula for the work done by an electric field?
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$W = qEd$. Work equals force times distance in uniform field.
$W = qEd$. Work equals force times distance in uniform field.
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What is the effect on potential energy if a charge is halved?
What is the effect on potential energy if a charge is halved?
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Halves. Energy is directly proportional to charge.
Halves. Energy is directly proportional to charge.
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What quantity does the symbol $U$ represent in electric energy equations?
What quantity does the symbol $U$ represent in electric energy equations?
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Electric potential energy. Standard symbol for electric potential energy in physics.
Electric potential energy. Standard symbol for electric potential energy in physics.
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Which physical quantity is conserved in an isolated electric system?
Which physical quantity is conserved in an isolated electric system?
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Electric energy. Total electric energy remains constant in isolated systems.
Electric energy. Total electric energy remains constant in isolated systems.
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State the formula for electric potential due to a point charge.
State the formula for electric potential due to a point charge.
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$V = k_e \frac{q}{r}$. Potential created by point charge $q$ at distance $r$.
$V = k_e \frac{q}{r}$. Potential created by point charge $q$ at distance $r$.
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Calculate the potential energy for $q = 3C$ and $V = -2V$.
Calculate the potential energy for $q = 3C$ and $V = -2V$.
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$U = -6 \text{ J}$. Using $U = qV = 3 \times (-2) = -6$ J.
$U = -6 \text{ J}$. Using $U = qV = 3 \times (-2) = -6$ J.
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State the principle of conservation of electric energy.
State the principle of conservation of electric energy.
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Total electric energy remains constant in an isolated system. Fundamental principle: energy cannot be created or destroyed.
Total electric energy remains constant in an isolated system. Fundamental principle: energy cannot be created or destroyed.
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How does electric potential vary with distance from a point charge?
How does electric potential vary with distance from a point charge?
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Inversely proportional. Potential follows inverse square law like electric field.
Inversely proportional. Potential follows inverse square law like electric field.
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What is the unit of Coulomb's constant $k_e$?
What is the unit of Coulomb's constant $k_e$?
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$\text{N} \cdot \text{m}^2/\text{C}^2$. Units derived from Coulomb's law force equation.
$\text{N} \cdot \text{m}^2/\text{C}^2$. Units derived from Coulomb's law force equation.
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State what happens to potential energy when a charge moves with the field.
State what happens to potential energy when a charge moves with the field.
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Decreases. Field does positive work, reducing potential energy.
Decreases. Field does positive work, reducing potential energy.
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How does electric potential energy change with distance in a uniform field?
How does electric potential energy change with distance in a uniform field?
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Decreases with distance. Energy decreases as charge moves with field direction.
Decreases with distance. Energy decreases as charge moves with field direction.
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Which physical quantity is conserved in an isolated electric system?
Which physical quantity is conserved in an isolated electric system?
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Electric energy. Total electric energy remains constant in isolated systems.
Electric energy. Total electric energy remains constant in isolated systems.
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State the formula for electric potential due to a point charge.
State the formula for electric potential due to a point charge.
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$V = k_e \frac{q}{r}$. Potential created by point charge $q$ at distance $r$.
$V = k_e \frac{q}{r}$. Potential created by point charge $q$ at distance $r$.
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Find the change in electric potential energy if $q = 2C$ and $\Delta V = 5V$.
Find the change in electric potential energy if $q = 2C$ and $\Delta V = 5V$.
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$\Delta U = 10 \text{ J}$. Using $\Delta U = q\Delta V = 2 \times 5 = 10$ J.
$\Delta U = 10 \text{ J}$. Using $\Delta U = q\Delta V = 2 \times 5 = 10$ J.
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What does the conservation of electric energy imply for potential changes?
What does the conservation of electric energy imply for potential changes?
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Sum of changes is zero. Net energy change is zero in conservative systems.
Sum of changes is zero. Net energy change is zero in conservative systems.
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Identify the relationship between electric field strength and potential difference.
Identify the relationship between electric field strength and potential difference.
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$E = -\frac{\Delta V}{d}$. Electric field is negative gradient of potential.
$E = -\frac{\Delta V}{d}$. Electric field is negative gradient of potential.
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What is the effect on potential energy if a charge is halved?
What is the effect on potential energy if a charge is halved?
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Halves. Energy is directly proportional to charge.
Halves. Energy is directly proportional to charge.
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What quantity does the symbol $U$ represent in electric energy equations?
What quantity does the symbol $U$ represent in electric energy equations?
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Electric potential energy. Standard symbol for electric potential energy in physics.
Electric potential energy. Standard symbol for electric potential energy in physics.
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Calculate the work done if a charge $q = 5C$ moves through $\Delta V = 3V$.
Calculate the work done if a charge $q = 5C$ moves through $\Delta V = 3V$.
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$W = 15 \text{ J}$. Using $W = q\Delta V = 5 \times 3 = 15$ J.
$W = 15 \text{ J}$. Using $W = q\Delta V = 5 \times 3 = 15$ J.
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State how electric potential energy changes when moving against the field.
State how electric potential energy changes when moving against the field.
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Increases. Moving against field requires work, increasing energy.
Increases. Moving against field requires work, increasing energy.
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What does the symbol $k_e$ represent in electric potential formulas?
What does the symbol $k_e$ represent in electric potential formulas?
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Coulomb's constant. Fundamental constant in Coulomb's law and electric formulas.
Coulomb's constant. Fundamental constant in Coulomb's law and electric formulas.
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Identify the effect on potential energy if distance increases in a point charge field.
Identify the effect on potential energy if distance increases in a point charge field.
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Decreases. Potential energy varies as $1/r$ for point charges.
Decreases. Potential energy varies as $1/r$ for point charges.
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Calculate the potential energy for $q = 3C$ and $V = -2V$.
Calculate the potential energy for $q = 3C$ and $V = -2V$.
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$U = -6 \text{ J}$. Using $U = qV = 3 \times (-2) = -6$ J.
$U = -6 \text{ J}$. Using $U = qV = 3 \times (-2) = -6$ J.
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What is the effect of increasing charge on electric potential energy?
What is the effect of increasing charge on electric potential energy?
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It increases linearly. Potential energy is directly proportional to charge.
It increases linearly. Potential energy is directly proportional to charge.
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What is the formula for the work done by an electric field?
What is the formula for the work done by an electric field?
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$W = qEd$. Work equals force times distance in uniform field.
$W = qEd$. Work equals force times distance in uniform field.
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Calculate the electric potential energy for $q = 4C$ and $V = 6V$.
Calculate the electric potential energy for $q = 4C$ and $V = 6V$.
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$U = 24 \text{ J}$. Using $U = qV = 4 \times 6 = 24$ J.
$U = 24 \text{ J}$. Using $U = qV = 4 \times 6 = 24$ J.
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Identify the formula for converting potential difference to electric field strength.
Identify the formula for converting potential difference to electric field strength.
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$E = -\frac{\Delta V}{d}$. Relationship between field strength and potential gradient.
$E = -\frac{\Delta V}{d}$. Relationship between field strength and potential gradient.
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Define the term 'electric potential'.
Define the term 'electric potential'.
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Work done per unit charge to move a charge from infinity. Potential is work per unit charge from reference point.
Work done per unit charge to move a charge from infinity. Potential is work per unit charge from reference point.
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What is the potential energy of a charge in a field with zero potential difference?
What is the potential energy of a charge in a field with zero potential difference?
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Zero. No potential difference means no stored energy.
Zero. No potential difference means no stored energy.
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