Physics Review Question Unit: Electricity Year: 1996 Question#: 29 Question: A metal conductor is used in an electric circuit. The electrical resistance provided by the conductor could be increased by (1 ) decreasing the length of the conductor (2 ) decreasing the applied voltage in the circuit (3 ) increasing the temperature of the conductor (4 ) increasing the cross-sectional area of the conductor What is this question really asking? Explanation by: Liz M [ Return to question menu ] Answer 1 decreasing the length of the conductor INCORRECT By decreasing the length of the conductor, the particles have less of the conductor to get through, therefore decreasing the resistance. This answer would achieve the oppisite of what the question is asking. return to top Answer 2 decreasing the applied voltage in the circuit INCORRECT Resistance is unaffected by a change in potential difference (unless it changes the temperature of the resistor). return to top Answer 3 increasing the temperature of the conductor CORRECT If the temperature of the metal is increased, then the particles that make up the conductor start to move faster making it harder for the charges to get through therefore increasing the resistance. return to top Answer 4 increasing the cross-sectional area of the conductor INCORRECT The bigger the cross -sectional area, the more space for charges to get through; therefore decreasing the resistance. This would achieve the opposite of what the question was looking for. return to top What's this question really asking? The question is asking you know how different properties can alter the electrical resistance of a metal conductor. return to top |
[Home] [Lessons] [Review] [Search] [Links]
This web site is designed and maintained by Science Joy Wagon and may
not be reproduced or redistributed without written permission from Science Joy Wagon. |