1.The sphere on the right has a charge of +2q. The sphere to the left has a charge of – 3q. Which of the following pictorial descriptions of the electric field best matches the above verbal description? A C B D

2.A student in an introductory physics class sees the following equation: Which of the following verbal descriptions best matches the above mathematical representation? (1.6 x C) (5.0 x 10 6 N/C) – 10 N = (0.015 kg) a A.A proton is in electric field that experiences a 10 N force holding it back. B.A kg object experiences just one force due to a 5.0 x 10 6 N/C electric field. C.A charged particle is accelerating in an electric field but also experiences a 10 N opposing force. D.A particle with charge of 1.6 x C is accelerated by a 10 N force.

3.Two charged spheres are brought together. The electric field measured at point A, points at a 45 o angle up and to the left. Which of the following pictures below matches the above description? A C B +q x x x x + √2 q x x A A A

4.A proton starts at rest between metal sheets with a potential difference of 100 Volts across them. Which motion diagram could match the proton’s motion when released? A C B D V init = 100 V V final = 0 V

A.Both pith balls are positively charged. B.Both pith balls are negatively charged. C.One pith ball is positively charged, the other is negatively charged. D.Both 1 and 2 are possible solutions 5.A picture is drawn below showing equipotential surfaces for two fixed charged pith balls. Which of the following verbal descriptions best match the above equipotential surfaces?

6.Three spheres with the same magnitude but different signs are shown below. Which electrical force diagram for objects corresponds to the pictorial representation? +q 1 +q 2 -q 3 A D C B

7.A student sees in a textbook the picture below of two charged spheres and the corresponding electric field lines. Which of the following verbal descriptions best matches the above pictorial representation? A.The two spheres have charges that are opposite but equal in magnitude. B.The left sphere has a positive charge that is twice the magnitude of the negative charge on the right. C.The left sphere has a negative charge that is twice the magnitude of the positive charge on the right. D.The right sphere must not have all of the lines drawn into it.

8.A positively charged sphere on the right is brought near a negatively charged sphere on the left with half the magnitude of electric charge. Which pair of electric force diagrams below best matches the verbal description above? x x x x A B C D

wxyzA+––+B–––+C––++D++++E+–+–wxyzA+––+B–––+C––++D++++E+–+– 9.Four charged spheres are placed at the corners of a square. The net electrical force at the center of the square is zero. What are the signs of the charged spheres to match the above verbal description? w x y z

10.A real situation is described mathematically: The same situation is described verbally below. Which description fits the above mathematical description best? A.A kg object is moving between the plates of a capacitor at a constant speed. B.A 1.0 x C object initially moves at some speed v away from a 12-V plate until it comes to rest at a 0-V plate. C.A kg charged object that is initially at rest at a 12-V plate moves away from the plate to a place at zero potential. D.The plate where the object arrives has no charge on it. ½ m v i 2 + q V a = ½ m v f 2 + q V b ½ (0.001 kg) (0 m/s) 2 + (1.0 x C) (12 V) = ½ (0.001 kg) v 2 + (1.0 x C) (0 V)

11.Suppose an object with a charge +5Q is fixed in place. An object with charge of -3Q sits at x distance away. Which of the following best illustrates the strength of the electric field as a function of distance? (Consider a field pointing to the right to be positive.) E x E x E x E x A C D B

12.Capacitors store charge. Which of the following graphs best represents the relationship between the charge held by a capacitor and distance between the plates of the capacitor? Q d A C D B Q d Q d Q d

Answers QAnswerQ 1D7B 2C8C 3B9A 4B10C 5D11A 6C12D