UNIVERSITY OF MASSACHUSETTS DARTMOUTH
COLLEGE OF ENGINEERING
EGR 101 INTRODUCTION TO ENGINEERING THROUGH APPLIED SCIENCE I
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This assignment is due Thursday, June 20, 2013.
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: 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
Refer to Figure 3.2 (a) on p. 77. What is the % setting of the potentiometer if its rated resistance
is 2.5k ?
Problem 3
Chapter 4: problem 5 on p. 122.
Problem 4
Chapter 4: problem 9 on p. 122.
Problem 5
Chapter 4: problem 13 on p. 122.
Problem 6
Chapter 4: problem 17 on p. 123.
Problem 7
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Find the % increase or decrease in resistance of a wire whose diameter is halved
Find the ratio of the resistance of copper to that of aluminum for two wires of the same
length and diameter.
Find the diameter of a copper wire that has the same length and resistance as an
aluminum wire having a diameter of 0.1 mm.
Problem 8
A battery provides 16,000 J of energy by virtue of the internal chemical reaction, which is
capable of moving 5 x 1020 e- through a wire.
 What is the charge Q in Coulomb (C)?
 What is the voltage of the battery in Volts (V)?
 What is the current in (μA) if the charges take 3 months to pass through a section of the
wire?