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Unformatted text preview: luu (nml299) HW09 markert (58710) 1 This print-out should have 21 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points Consider a transformer. What is true? 1. A transformer works with direct cur- rent. 2. A transformer does not work with direct current. 002 10.0 points What device increases or decreases the volt- age of alternating current? 1. circuit breaker. 2. generator. 3. transformer. 4. motor. 003 (part 1 of 2) 10.0 points A hair drier uses 10 A at 113 V. It is used with a transformer in England, where the line voltage is 244 V. What should be the ratio of the turns of the transformer (primary to secondary)? 004 (part 2 of 2) 10.0 points What current will it draw from the 244 V line? Answer in units of A. 005 10.0 points How does the current in the secondary of the transformer compare with the current in the primary when the secondary voltage is twice the primary voltage? 1. half the current in the primary 2. the same as the current in the primary 3. Sometimes these two currents are not related to each other. 4. twice the current in the primary 006 10.0 points Would electromagnetic waves exist if chang- ing magnetic fields could produce electric fields, but changing electric fields could not in turn produce magnetic fields? 1. Yes; as long as we have a magnet, there is a magnetic field to form the electromagnetic waves....
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This note was uploaded on 09/22/2010 for the course PHY 58710 taught by Professor Markert during the Spring '09 term at University of Texas at Austin.
- Spring '09