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Review Capacitance Resistance RC circuits Kirchoff’s laws Course Evaluation at the end of class Instructions for Students Completing Course Evaluations Access URL: http://www.compusurvey.ca/uoit/ca/ 2. Log-in: enter your 9 digit student ID 10……… enter your date of birth Then click “log-in” You will see a drop-down list of all courses you are taking. Follow the instructions there to access and complete only the surveys for this course and professor, including surveys for labs or tutorials which are part of this course. If you have more than one professor for this course, be sure to complete a separate survey for each. When you have completed each survey, click the “SUBMIT” box. When you are finished, click the “LOG OUT” box. Instructor Franco Gaspari PHY 1040U (Physics for the biosciences) Introduction to Electromagnetism and Optics Lecture 17 March 13, 2006 16. Two capacitors, C1 = 5.00 ?F and C2 = 12.0 ?F, are connected in parallel, and the resulting combination is connected to a 9.00-V battery. (a) What is the equivalent capacitance of the combination? What are (b) the potential difference across each capacitor and (c) the charge stored on each capacitor? 22. Three capacitors are connected to a battery as shown in Figure P26.22. Their capacitances are C1 = 3C, C2 = C, and C3 = 5C. (a) What is the equivalent capacitance of this set of capacitors? (b) State the ranking of the capacitors according to the charge they store, from largest to smallest. (c) Rank the capacitors according to the potential differences across them, from largest to smallest. (d) What If? If C3 is increased, what happens to the charge stored by each of the capacitors? 48. A wafer of titanium dioxide (? = 173) of area 1.00 cm2 has a thickness of 0.100 mm. Aluminum is evaporated on the parallel faces to form a parallel-plate capacitor. (a) Calculate the capacitance. (b) When the capacitor is charged with a 12.0-V battery, what is the magnitude of charge delivered to each plate? 14. A resistor is constructed of a carbon rod that has a uniform cross-sectional area of 5.00 mm2. When a potential difference of 15.0 V is applied across the ends of the rod, the rod carries a current of 4.00 × 10–3 A. Find (a) the resistance of the rod and (b) the rod’s length. 16. A conductor of uniform radius 1.20 cm carries a current of 3.00 A produced by an electric field of 120 V/m. What is the resistivity of the material? 8. Four copper wires of equal length are connected in series. Their cross-sectional areas are 1.00 cm2, 2.00 cm2, 3.00 cm2, and 5.00 cm2. A potential difference of 120 V is applied across the combination. Determine the voltage across the 2.00-cm2 wire. 24. Using Kirchhoff’s rules, (a) find the current in each resistor in Figure P28.24. (b) Find the potential difference between points c and f. Which point is at the higher potential? 31. Consider a series RC circuit for which R = 1.00 M?, C = 5.00 ?F, and ? = 30.0 V. Find (a) the time constant of the circuit and (b) the maximum charge on the capacitor after the switch is closed. (c) Find the current in the resistor 10.0 s after the switch is closed.