Materials Assignement 3 Attempt 2

# Materials Assignement 3 Attempt 2 - WebCT Quiz Homepage...

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http://webct.mcmaster.ca/SCRIPT/MATLS_1M03_T2_06_newRestore/s. .. 1 of 4 17/02/2006 7:23 PM View Results Name: BRYCE JONES Attempt: 2 / 3 Out of: 27 Started: February 17, 2006 12:41am Finished: February 17, 2006 4:06am Time spent: 3 hr, 24 min., 45 sec. Question 1 (2 points) The conductivity of a 3.76 mm-diameter cylindrical silicon specimen if found to be 22.2 (Ohm-m) -1 . Calculate the resistance (in Ohm) of a 42.9 mm length of the specimen. Use decimal notation, digits after decimal: 0 Student response: 174 Ohm Correct answer: 174 Ohm General feedback: To solve this question you need to know the difference between conductivity and resistivity. For more information, see page 613 of the text. Equation 18.2 is also useful. Score: 2 / 2 Question 2 (1 point) The typical electrical conductivity value/range for semiconducting materials is: Student response: Correct Response Student Response Answer Choices a. 10 7 (Ω-m) -1 b. 10 -20 to 10 -10 (Ω-m) -1 c. 10 -6 to 10 4 (Ω-m) -1 General feedback: Semiconducting materials typically have electrical conductivities in the range of 10 -6 to 10 4 (Ω-m) -1 . See page 614 of the text. Score: 1 / 1 Question 3 (1 point) True or False? All electrons present in a material are available to participate in the conduction process. Student response: Correct Response Student Response Answer Choices a. True b. False General feedback: False . The number of electrons available for electrical conduction in a particular material is related to the arrangement of electron states or levels with respect to energy, and the manner in which these states are occupied by electrons. See page 614 of the text for more information. Score: 1 / 1 Question 4 (2 points) True or False? In a perfect crystal (i.e., without any imperfections), application of an electric field will result in a continuously increasing electric current with time. Student response: Correct Response Student Response Answer Choices a. True b. False General feedback: True . For more information see page 619 in the text. Score: 2 / 2 Question 5 (2 points) Estimate the electrical resistivity (in Ohm-m) of metal Y containing 1.79 at% of metal Z at 142°C, given the following material constants: ρ 0 a A for one in the other (Omega-m) (Omega-m/°C) (Omega-m) 1.29 x 10 -8 5.21 x 10

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## This note was uploaded on 02/08/2010 for the course MATLS 1M03 taught by Professor Okon during the Winter '09 term at McMaster University.

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Materials Assignement 3 Attempt 2 - WebCT Quiz Homepage...

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