Qwizdom questions for Dec. 17, 2009

16. Which of the following is not a vector? A. electric force B. electric field C. electric potential D. electric line of force

16. The correct answer is C, electric potential, V.

17. One joule per coulomb is a A. newton B. volt C. electron-volt D. farad

17. The answer is B, a volt. Recall that So, using units: 1 volt = 1 joule/coulomb

18.The potential at a distance of 2.0 m from a positive point charge is 100 V. What is the potential 4.0 m away from the same point charge? A. 25 V B. 50 V C. 200 V D. 400 V

18. The answer is B, 50 volts. So if r is doubled, V will be ½ as large.

19.The potential at the exact center of a square is 3.0 V when a charge of +Q is located at one of the square's corners. What is the potential at the square's center when each of the other corners is also filled with a charge of +Q? A) zero B) 3.0 V C) 9.0 V D) 12 V

19. The correct answer is D, 12 V. Since V is a scalar quantity and the distance from the center to each corner is the same,

20. The electron-volt is a unit of A. voltage B. current C. power D. energy

20. The correct answer is D, energy.

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