Electric Potential Quiz with Answers: Test Your Physics Knowledge

📚 Quick Study Guide

• ⚡ Electric Potential (V): The amount of work needed to move a unit positive charge from a reference point to a specific point in an electric field. Measured in volts (V).
• 💡 Formula: $V = \frac{W}{q}$, where V is electric potential, W is work done, and q is the charge.
• 📊 Potential Difference ($\Delta V$): The difference in electric potential between two points. $\Delta V = V_B - V_A$
• 🌍 Electric Field (E): The negative gradient of the electric potential. $E = -\frac{dV}{dr}$
• ⚛️ Equipotential Surfaces: Surfaces where the electric potential is constant. No work is required to move a charge along an equipotential surface.
• ➕ Potential due to a point charge: $V = \frac{kQ}{r}$, where k is Coulomb's constant, Q is the charge, and r is the distance from the charge.
• 🛡️ Superposition Principle: The total electric potential at a point due to multiple charges is the algebraic sum of the potentials due to each charge.

🧪 Practice Quiz

1. What is the electric potential at a point 2 meters away from a point charge of 5 μC? (k = 9 x 10^9 Nm²/C²)

   1. 2.25 x 10^4 V
   2. 4.5 x 10^4 V
   3. 9 x 10^4 V
   4. 1.125 x 10^4 V

2. The electric potential at point A is 20 V and at point B is 40 V. How much work is required to move a charge of -2 C from A to B?

   1. -40 J
   2. 40 J
   3. -120 J
   4. 120 J

3. What is the relationship between electric field (E) and electric potential (V)?

   1. $E = -\frac{dV}{dr}$
   2. $E = \frac{dV}{dr}$
   3. $V = -\frac{dE}{dr}$
   4. $V = \frac{dE}{dr}$

4. Which of the following statements is true about equipotential surfaces?

   1. Electric field is always parallel to the surface.
   2. No work is done in moving a charge along the surface.
   3. Electric potential is maximum on the surface.
   4. Electric field is zero on the surface.

5. Two charges, +q and -q, are placed a small distance apart. What is the electric potential at a point exactly midway between the two charges?

   1. Zero
   2. Positive
   3. Negative
   4. Depends on the magnitude of q

6. The electric potential at a certain point in space is 100 V. If a charge of +2 C is placed at that point, what is the electric potential energy of the charge?

   1. 50 J
   2. 100 J
   3. 200 J
   4. 400 J

7. If the electric potential is constant throughout a region of space, what can be said about the electric field in that region?

   1. It is constant and non-zero.
   2. It is zero.
   3. It is increasing linearly.
   4. It is decreasing linearly.