GEOPH424 Final: GEOPHYS 424 UofA Final Exams 2010 424 Final
Document Summary
Cell phones and all other electronic devices must be switched off and stored. All questions must be directed to the invigilator. A separate 2 page formula sheet is available. Question 1 : resistivity of rocks (total = 11 points) (a) electric current flows in a material that contains a single type of charge carrier. There are n charge carriers per unit volume and each has a charge q. The charge carriers have a mobility which is defined as the drift velocity per unit electric field. v. Show that the electrical conductivity of the material is given by (6 points) qn (b) a brine is formed by dissolving 9 g of sodium chloride in 1 litre of water. The brine has a conductivity of 1 s/m. Assume that the sodium (na+) and chloride ( cl- ) ions have the same mobility (5 points) Question 2 : ground-penetrating radar (total = 7 points)
