Electric Potential Energy Quiz with Answers: Test Your Knowledge

📚 Quick Study Guide

• ⚡ Electric potential energy ($U$) is the energy a charge possesses due to its location in an electric field.
• 🔢 The electric potential energy between two point charges $q_1$ and $q_2$ separated by a distance $r$ is given by: $U = k \frac{q_1 q_2}{r}$, where $k$ is Coulomb's constant ($k \approx 8.99 \times 10^9 \text{ N m}^2/\text{C}^2$).
• 📍 Electric potential ($V$) is the electric potential energy per unit charge: $V = \frac{U}{q}$.
• 🌍 The change in electric potential energy ($\Delta U$) is related to the work done by the electric force: $\Delta U = -W$.
• 💡 When dealing with multiple charges, the total electric potential energy is the sum of the potential energies due to all pairs of charges.
• 📝 Electric potential energy is a scalar quantity; it has magnitude but no direction.

Practice Quiz

1. What is the electric potential energy between two charges of +2 μC and -3 μC separated by a distance of 20 cm?
   1. -0.27 J
   2. 0.27 J
   3. -0.54 J
   4. 0.54 J
2. If the electric potential at a point is 500 V, how much work is required to bring a charge of +4 μC from infinity to that point?
   1. 2 mJ
   2. -2 mJ
   3. 4 mJ
   4. -4 mJ
3. A charge of +5 nC is moved from a point with an electric potential of 200 V to a point with an electric potential of 300 V. What is the change in electric potential energy of the charge?
   1. 0.5 μJ
   2. 1.0 μJ
   3. 1.5 μJ
   4. 2.0 μJ
4. Two identical positive charges are placed a certain distance apart. If the distance between them is doubled, what happens to the electric potential energy of the system?
   1. It doubles.
   2. It halves.
   3. It quadruples.
   4. It is quartered.
5. What is the electric potential energy of a system of three charges, each +1 μC, placed at the vertices of an equilateral triangle with sides of 10 cm?
   1. 0.81 J
   2. 0.27 J
   3. 0.54 J
   4. 0.18 J
6. A proton (charge +e) is accelerated from rest through a potential difference of 1000 V. What is the change in its electric potential energy?
   1. $1.602 \times 10^{-16}$ J
   2. $-1.602 \times 10^{-16}$ J
   3. $1.602 \times 10^{-22}$ J
   4. $-1.602 \times 10^{-22}$ J
7. If the electric potential energy of a charge is zero at a certain point, what can be said about the electric field at that point?
   1. The electric field must be zero.
   2. The electric field must be non-zero.
   3. The electric field could be zero or non-zero.
   4. The electric field is infinite.