Physics Review Question Unit: electricity and magnetism Year: 1989 Question#: 30 Question: How much energy is required to move 3.2 x 10-19 coulomb of charge through a potential difference of 5 volts? (1 ) 5 eV (2 ) 2 eV (3 ) 10 eV (4 ) 20 eV What is this question really asking? Explanation by: Allison B. [ Return to question menu ] Answer 1 5 eV INCORRECT This answer is incorrect. Try using the formula: V = W/q. Remember, energy is stored work. return to top Answer 2 2 eV INCORRECT This answer is incorrect. Try using the formula: V = W/q. Remember, energy is stored work. return to top Answer 3 10 eV CORRECT Since energy is stored work, we can use the formula: V = W/q or (rearranged), W = Vq. Voltage = 5V, charge = 3.2 X 10-19C which is equivalent to 2 elementary charges, so work = 10 eV. return to top Answer 4 20 eV INCORRECT This answer is incorrect. Try using the formula: V = W/q. Remember, energy is stored work. return to top What's this question really asking? This question is asking how much work has been done in moving a charge. It is also testing your ability to change large units of charge (coulombs) into small units of charge (elementary charges). return to top |
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