Physics II Test 1 Quiz questions

A test charge of +3 µC is at a point P where an external electric field is directed to the right and has a magnitude of 4 ✕ 106 N/C. If the test charge is replaced with another test charge of -3 µC, the external electric field at P does which of the following? A. is unaffected B. changes in a way that cannot be determined C. reverses direction

A

Suppose you have a sphere of radius 1.00 m that carries a charge of +1.00 µC at its center. The radius of the sphere is changed to 0.500 m. What happens to the flux through the sphere and the magnitude of the electric field at the surface of the sphere? A) The flux remains the same and the field increases. B) The flux decreases and the field increases. C) The flux and field both decrease. D)The flux and field both increase. E) The flux increases and the field decreases. F) The flux decreases and the field remains the same

A

Object A has a charge of +2 µC, and object B has a charge of +6 µC. Which statement is true about the electric forces on the objects? A. FAB = -3FBA B. FAB = -FBA C. FAB = 3FBA D. 3FAB = -FBA E. 3FAB = -FBA F. FAB = FBA

B

Your younger brother likes to rub his feet on the carpet and then touch you to give you a shock. While you are trying to escape the shock treatment, you discover a hollow metal cylinder in your basement, large enough to climb inside. In which of the following cases will you not be shocked? A) Your charged brother is inside touching the inner metal surface and you are outside, touching the outer metal surface. B) You climb inside the cylinder, making contact with the inner surface, and your charged brother touches the outer metal surface. C) Both of you are outside the cylinder, touching its outer metal surface but not touching each other directly.

B

A charged comb often attracts small bits of dry paper that then fly away when they touch the comb. Explain why that occurs.

Because the comb is negative, it initially attracts small pieces of paper. However, as the comb touches the paper, electrons are transferred to it, causing it to be negatively charged. The negative charges on both objects causes them to repel one another

If the net flux through a Gaussian surface is zero, the following four statements could be true. Which of the statements must be true? A) The electric field is zero everywhere on the surface. B) There are no charges inside the surface. C) The net charge inside the surface is zero. D) The number of electric field lines entering the surface equals the number leaving the surface.

C and D

Three objects are brought close to each other, two at a time. When objects A and B are brought together, they repel. When objects B and C are brought together, they also repel. Which of the following are true? A. One object is neutral. B. Objects A and C possess charges of opposite sign. C. Objects A and C possess charges of the same sign. D. All three objects possess charges of the same sign. E. Additional experiments must be performed to determine the signs of the charges

C, D, E

Rank the magnitudes of the electric field at points A, B, and C shown in the figure below (greatest magnitude first) A) A > C > B B) C > B > A C) B > A > C D) C > A > B E) B > C > A F) A > B > C

F

A student who grew up in a tropical country and is studying in the United States may have no experience with static electricity sparks and shocks until their first American winter. Explain.

In a tropical country, the air is very humid, which helps dissipate static charge. In America, winters can be very dry and thus conducive to static build up