An electron and a proton are separated by a distance of 1 m. What happens to the size of the force on proton if a second electron is placed next to rst electron? a. It will increase to twice its original size. b. It will increase to four times its original size. 6. It will not change. d. It will decrease to one-half its original size. Sphere A carries a net positive charge and sphere B is neutral. They are placed near each other on an insulated table. Sphere B is briey touched with a wire that is grounded. Which statement is correct? a. Sphere B is still neutral. b. Sphere B is now positively charged. c. Sphere B is now negatively charged. d. It is impossible to say anything about the charge on sphere B from the information given. A point charge of +0 is placed at the exact center of a square and second point charge of Q is placed at one of the square's corners. It is observed that an electrostatic force of 2 N acts on the positive charge at the square's center. What is the magnitude of the electrostatic force which acts on the positive charge if identical negative charges of Q are placed at the other three corners of the square? a. zero. b. 4 N. c. 8 N. d. None of the above. Two charged object attract each other with a force F. What happens to the force between them if one charge is doubled, the other charge is tripled, and the distance of separation between their centers reduced to one-fourth its original value? The force is now equal to a. 16 F. b. 24 F. c. (6/16) F. d. 96 F. Two point charges are placed along a horizontal axis with the following values and positions; +3.0 [10 at x = 0 cm and 7.0 [10 at x = 20 cm. At what point along the x axis is the electric field zero? a. 8.0 cm. b. - 44 cm. c. - 69 cm. d. - 38 cm A proton initially moves left to right along the x axis at a speed of 2.00 x 103 m/s. It moves into an electric field, which points in the negative x direction, and travels a distance of 0.200 rn before coming to rest. What is the magnitude of the electric field? a. 28.3 NC. b. 13.9 NC. c. 0.104 N/C. d. 0.038 NIC. A large negatively charged object is placed on a wooden table. A neutral metallic ball rolls straight towards the object but stops before it touches it. A second neutral metallic ball rolls up along the path followed by the rst ball, strikes the first ball driving it a bit closer to the negatively charged object and steps. After all balls have stopped rolling, the rst ball is closer to the negatively charged object than is the second ball. At no time did either ball touch the charged object. Which statement is correct concerning the nal charge on each ball? a. The rst ball is positive and second is negative. b. the first ball is negative and second is positive. c. Both balls remain neutral. d. Both balls are positive. Four charges are at the corners of a square, with B and C on opposite corners. Charges A and D, on the other two comers, have equal charge. while both B and C have a charge of +1.0 C. What is the charge on A so that the force on B is zero? A B a. - 1.0 C. b. - 0.50 C. c. - 0.35 C. d. - 0.71 C. C D An electron with a speed of 2.0 x 106 m/s moves into a uniform electric field of 500 N10 that is parallel to the electron's motion. How long does it take to bring the electron to rest? a. 2.3 x10'8 3. b. 3.5 x103 5. c. 1.2 x10'7 5. d. 2.3 x10'6 5. Electrons in a particle beam each have a kinetic energy of 3.2 x 10'17 J. What is the magnitude of the electric field that will stop these electrons in a distance of 0.1 m? a. 200 NIC. b. 1000 WC. c. 2000 MC. d. 4000 NC. A particle (charge = +40 110) is located on the x axis at the point x = 20 cm, and a second particle (charge = 50 HO) is placed on the x axis at x = +30 cm. What is the magnitude of the total electrostatic force on a third particle (charge = 4.0 pC) placed at the origin (x = 0)? a. 41 N b. 16 N c. 56 N d. 35 N e. 72 N Three point charges, two positive and one negative. each having a magnitude of 20 110 are placed at the vertices of an equilateral triangle (30 cm on a side). What is the magnitude of the electrostatic force on the negative charge? a. 80 N b. 40 N c. 69 N d. 57 N e. 75 N