ENGG250 ASSIGNMENT 1
ENGG250 MATERIALS
ASSIGNMENT 1
20 marks
DUE: 20 MARCH 2015
These are the sort of questions you can expect in the Class Test on 23 March. Completing this assignment should therefore be considered part of your preparation for the Class Test.
(The Class Test will cover more material than the assignment).
When you have completed the questions, make an electronic file from your answers (you can put together an electronic file, or scan your handwritten copy – as long as it is legible).
Create a cover sheet, using the FoS version at http://web.science.mq.edu.au/intranet/lt/barcode/coversheet.php Then make a single .pdf file containing both your answers and the cover sheet, and upload it to iLearn.
1. Select two simple household items (examples might be a floor rug, a picture frame, a cooking pot, a plate – think of your own, don’t include any of these). Complete the following table. You are not expected to analyse chemical composition or carry out testing, so a guess is fine – but it should be an educated guess;
Household
item
Predominant material type: ceramic/polymer/ metal/’composite
Electrical resistivity – high or low?
Why? (i.e. explain your answer) Ductile or brittle?
Why? (i.e. explain your answer)
[4 marks]
2.
A current of 1A flows in a metal rod which is 10 cm long and 1 mm in diameter.
(a) What is the resistance of the rod if it is made from silver? From copper? What is the voltage between the ends of the rod, for silver? For copper?
If the length of the rod is doubled to 20 cm,
(b) Will the resistance change? By how much? Will the resistivity change?
By how much?
(c) Which material would be better for long-distance electrical transmission
(power lines)?
Why?
Would you pick this material if you were the engineer in charge of materials selection? Why/why not?
Cu = 1.7 -cm
[8 marks]
Ag = 1.5-cm
3.
(a) A plane of atoms in a simple cubic lattice intersects the x axis at x = 4. The plane is parallel to the y axis and the z axis. What is the
ASSIGNMENT 1
20 marks
DUE: 20 MARCH 2015
These are the sort of questions you can expect in the Class Test on 23 March. Completing this assignment should therefore be considered part of your preparation for the Class Test.
(The Class Test will cover more material than the assignment).
When you have completed the questions, make an electronic file from your answers (you can put together an electronic file, or scan your handwritten copy – as long as it is legible).
Create a cover sheet, using the FoS version at http://web.science.mq.edu.au/intranet/lt/barcode/coversheet.php Then make a single .pdf file containing both your answers and the cover sheet, and upload it to iLearn.
1. Select two simple household items (examples might be a floor rug, a picture frame, a cooking pot, a plate – think of your own, don’t include any of these). Complete the following table. You are not expected to analyse chemical composition or carry out testing, so a guess is fine – but it should be an educated guess;
Household
item
Predominant material type: ceramic/polymer/ metal/’composite
Electrical resistivity – high or low?
Why? (i.e. explain your answer) Ductile or brittle?
Why? (i.e. explain your answer)
[4 marks]
2.
A current of 1A flows in a metal rod which is 10 cm long and 1 mm in diameter.
(a) What is the resistance of the rod if it is made from silver? From copper? What is the voltage between the ends of the rod, for silver? For copper?
If the length of the rod is doubled to 20 cm,
(b) Will the resistance change? By how much? Will the resistivity change?
By how much?
(c) Which material would be better for long-distance electrical transmission
(power lines)?
Why?
Would you pick this material if you were the engineer in charge of materials selection? Why/why not?
Cu = 1.7 -cm
[8 marks]
Ag = 1.5-cm
3.
(a) A plane of atoms in a simple cubic lattice intersects the x axis at x = 4. The plane is parallel to the y axis and the z axis. What is the