Mastering Physics: Electric Potential, Potential Energy, and Force

Mastering Physics: Electric Potential, Potential Energy, and Force

Part A

Question: Electric field lines always begin at _______ charges (or at infinity) and end at _______ charges (or at infinity). One could also say that the lines we use to represent an electric field indicate the direction in which a _______ test charge would initially move when released from rest. Which of the following fills in the three missing words correctly?

Answer:  (positive; negative; positive)

Part B

Question: Would a positive test charge released from rest move toward a region of higher or lower electric potential (compared to the electric potential at the point where it is released)?

Answer: lower electric potential

Part C

Question: Now imagine that the sign of our test particle is changed from positive to negative, but the electric potential remains the same. Which of the following statements is correct?

Answer: The direction of the force will change and it will point to regions of lower potential energy.