Chapter 17 Misconceptual Questions

A +0.2 uC charge is in an electric field. What happens if that charge is replaced by a +0.4 uC charge? A. The electric potential stays the same, but the electric potential energy doubles. B. The electric potential doubles, but the electric potential energy stays the same. C. Both the electric potential and electric potential energy double. D. Both the electric potential and electric potential energy stay the same.

Two identical positive charges are placed near each other. At the point halfway between the two charges, A. the electric field is zero and the potential is zero. B. the electric field is not zero and the potential is zero. C. the electric field is zero and the potential is positive. D. the electric field is not zero and the potential is positive. E. None of these statements is true.

Four identical point charges are arranged at the corners of a square [Hint: Draw a figure]. The electric field E and potential V at the center of the square are A. E = 0, V = 0. B. E ≠ 0, V ≠ 0. C. E = 0, V ≠ 0. D. E ≠ 0, V = 0. E. E = V regardless of the value.

Which of the following statements is valid? A. If the field throughout a particular region is constant, the potential throughout that region must be zero. B. If the field at a particular point is zero, the potential at that point must be zero. C. If the potential at a particular point is zero, the field at that point must be zero. D. If the potential throughout a particular region is constant, the field throughout that region must be zero.

A proton Q = +e and an electron Q = -e are in a constant electric field created by oppositely charged plates. You release the proton from near the positive plate and the electron from near the negative plate. Which feels the larger electric force? A. The proton. B. The electron. C. Neither−there is no force. D. The magnitude of the force is the same for both and in the same direction. E. The magnitude of the force is the same for both but in opposite directions.

A proton (Q = +e) and an electron (Q = -e) are in a constant electric field created by oppositely charged plates. You release the proton from near the positive plate and the electron from near the negative plate. When the proton and electron strike the opposite plate, which one has more kinetic energy? A. The electron. B. The proton. C. Both acquire the same kinetic energy. D. Neither−there is no change in kinetic energy. E. They both acquire the same kinetic energy but with opposite signs.

Which of the following do not affect capacitance? Check all that apply. A. Energy stored in the capacitor. B. Separation of the plates. C. Area of the plates. D. Charge on the plates. E. Material between the plates.

A battery establishes a voltage V on a parallel-plate capacitor. After the battery is disconnected, the distance between the plates is doubled without loss of charge. Accordingly, the capacitance _________ and the voltage between the plates __________.

Which of the following is a vector? A. Electric field. B. Capacitance. C. Electric potential. D. Equipotential lines. E. Electric potential energy.

A +0.2 μC charge is in an electric field. What happens if that charge is replaced by a -0.2 μC charge? A. The electric potential stays the same, but the electric potential energy changes sign. B. The electric potential changes sign, but the electric potential energy stays the same. C. Both the electric potential and electric potential energy change sign. D. Both the electric potential and electric potential energy stay the same.

What property of objects is best measured by their capacitance? A. the ability to conduct electric current B. the ability to distort an external electrostatic field C. the ability to store charge

Consider an air-filled charged capacitor. How can its capacitance be increased? A. Increase the charge on the capacitor. B. Decrease the charge on the capacitor. C. Increase the spacing between the plates of the capacitor. D. Decrease the spacing between the plates of the capacitor. E. Increase the length of the wires leading to the capacitor plates.

Consider a charged parallel-plate capacitor. How can its capacitance be halved? Check all that apply. A. Double the charge. B. Double the plate area. C. Double the plate separation. D. Halve the charge. E. Halve the plate area. F. Halve the plate separation.

Consider a charged parallel-plate capacitor. Which combination of changes would quadruple its capacitance? A. Double the charge and double the plate area. B. Double the charge and double the plate separation. C. Halve the charge and double the plate separation. D. Halve the charge and double the plate area. E. Halve the plate separation and double the plate area. F. Double the plate separation and halve the plate area.