Electric Potential - AP Physics 2

1. What is the electric potential energy of a $2C$ charge at $3V$?

   $6 \text{ J}$. Using $U = qV = 2 \times 3 = 6$.

2. How is work done related to electric potential difference?

   $W = q \triangle V$. Standard work-voltage relationship formula.

3. What is the formula for electric potential energy?

   $U = qV$. Energy equals charge times potential.

4. What is the potential difference between two points in a $4V$ and $10V$ field?

   $6 \text{ V}$. Difference equals $10 - 4 = 6$ volts.

5. Define electric potential.

   Electric potential is the work done per unit charge. Describes energy per unit charge at a point.

6. Define the term 'electric potential energy'.

   Energy a charge has due to its position in an electric field. Energy stored due to electric field position.

7. Calculate the work done in moving a charge of $2C$ through a potential difference of $5V$.

   $10 \text{ J}$. Work equals charge times potential difference: $W = qV = 2 \times 5 = 10$.

8. What is the electric potential at a point equidistant from two equal charges?

   Zero. Equal charges create symmetric cancellation.

9. State the relationship between potential difference and electric field.

   $E = -\frac{\triangle V}{d}$. Field strength relates to potential gradient.

10. What is the potential energy of a charge in a uniform electric field?

    $U = qEd$. Energy stored in uniform field configuration.

11. Which quantity is measured in volts?

    Electric potential. Voltage measures electric potential difference.

12. What is the relation between potential difference and energy change?

    $\triangle U = q \triangle V$. Energy change equals charge times voltage change.

13. Calculate the potential at a point $3m$ from a $5C$ charge.

    $V = \frac{k \times 5}{3}$. Direct substitution into point charge formula.

14. Calculate the potential energy of $5C$ in a $4V$ potential.

    $20 \text{ J}$. Using $U = qV = 5 \times 4 = 20$.

15. Find the electric field from a potential function $V(x) = 3x^2$.

    $E = -6x \text{ V/m}$. Field equals negative derivative: $E = -\frac{dV}{dx} = -6x$.

16. State the formula for potential energy in terms of electric field and distance.

    $U = qEd$. Energy from charge, field, and displacement.

17. Calculate the potential difference for a $4V$ and $12V$ junction.

    $8 \text{ V}$. Difference equals $12 - 4 = 8$ volts.

18. What is the formula for electric potential difference?

    $\triangle V = V_f - V_i$. Change in potential equals final minus initial.

19. State the formula for the potential energy of a system of two charges.

    $U = \frac{kq_1q_2}{r}$. Interaction energy between two point charges.

20. State the formula for the electric potential due to a point charge.

    $V = \frac{kq}{r}$. Coulomb's law for potential from point charge.

21. What is the electric potential at infinity?

    Zero. Reference point for electric potential measurements.

22. How is potential difference related to work done on a charge?

    $W = q \triangle V$. Fundamental relationship between work and voltage.

23. How is the work done on a charge related to potential difference?

    $W = q \triangle V$. Work done equals charge times voltage change.

24. State the unit of electric potential energy.

    Joule (J). Standard unit for measuring energy quantities.

25. What is the potential energy of a $3C$ charge at a potential of $4V$?

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

26. Define the term 'equipotential surface'.

    A surface with constant electric potential. Surface where potential remains constant everywhere.

27. Calculate the potential energy of a $2C$ charge in a $10V$ field.

    $20 \text{ J}$. Using $U = qV = 2 \times 10 = 20$.

28. Identify the relationship between electric potential and electric field.

    $E = -\nabla V$. Electric field is negative gradient of potential.

29. Identify the potential difference needed to store $20J$ in $2C$ of charge.

    $10 \text{ V}$. From $U = qV$, solve for $V = \frac{U}{q} = \frac{20}{2} = 10$.

30. What is the potential at a point midway between two equal charges?

    Zero. Symmetric positioning cancels equal contributions.

31. Find the potential energy of $3C$ in a $6V$ field.

    $18 \text{ J}$. Using $U = qV = 3 \times 6 = 18$.

32. Find the potential difference if the electric field is $5 \text{ V/m}$ across $3m$.

    $15 \text{ V}$. Using $\triangle V = Ed = 5 \times 3 = 15$.

33. How is electric potential related to electric potential energy?

    $V = \frac{U}{q}$. Potential equals energy per unit charge.

34. Identify the potential energy formula for a system of charges.

    $U = \frac{kq_1q_2}{r}$. Standard formula for charge interaction energy.

35. What is the formula for the potential difference in a uniform field?

    $\triangle V = Ed$. Potential difference in uniform electric field.

36. State the unit of electric potential.

    Volt (V). Standard unit for measuring electric potential.

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