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UNIVERSITY OF MASSACHUSETTS DARTMOUTH COLLEGE OF ENGINEERING EGR 101 INTRODUCTION TO ENGINEERING I This assignment is due Thursday, October 11, 2012. Use engineering papers. Show all of your steps. Present your work neatly and clearly. Box your final answers. Problem 1 Resistors are rated not only in terms of resistance, but also in terms of their ability to dissipate power without burning. For example, if you use a resistor rated to dissipate 2 W in a circuit where the voltage and current conditions require that the wire dissipates 3 W then the wire will burn, and the circuit may be damaged. The ratings of resistors are given in section 2.3.5. on p. 56. Chapter 3: solve problem 15 on p. 93, and refer to section 2.3.5 on p. 56 in order to select the required power rating. Problem 2 Chapter 3: problem 27 on p. 94. The range of possible current values is found by calculating the minimum and maximum V values of the current. If you consider Ohm’s law in the form of I , then you can R infer that for fixed voltage, as R increases, I decreases, and vice versa. Use the 4-band color code of the resistor to find its nominal value and tolerance. From this information find the minimum and maximum values of resistance and the corresponding currents. Problem 4 Refer to Figure 3.2 (a) on p. 77. What is the % setting of the potentiometer if its resistance rating is 2.5k ? Problem 5 Chapter 4: problem 5 on p. 122. Problem 6 Chapter 4: problem 9 on p. 122. Problem 7 Chapter 4: problem 13 on p. 122. Problem 8 Chapter 4: problem 17 on p. 123.