MAE 2055: Mechetronics I
Mechanical and Aerospace Engineering
Fall 2013
Homework 2
1) For the following circuit, find values of R1 to satisfy each of the following conditions:
a) V = 4 V
b) V = 12 V
c) I = 2 A
d) The power, P1, dissipated in R1 is 20 W. (There are two possible values for R1. Find both.)
3Ω
I
+
+
16V
V
R1
-
2) Find the equivalent resistance, Req, between the terminals of each of the following networks.
R2
R1
R2
R1
R3
R4
R3
(a)
(b)
R1
R2
R3
R2
R4
R3
R1
R4
(c)
(d)
R1
R3
R3
R5
R2
R2
R4
R1
R1 = R2 = 2500Ω, R3 = R4 =500Ω
(e)
R1
R4
R1 = R2 = 800Ω, R3 = R4 =400Ω, R5 = 600Ω
(f)
R1
R5
R2
Hint for part (g): Note the equal-valued resistors.
What does this tell you?
R2
R1 = 1250Ω, R2 = 400Ω, R5 = 50Ω
(g)
3) Apply Kirchhoff’s voltage law to the following circuit. That is, write an equation for the sum of
voltage drops around the loop. (Your expression will include the unknown variables I, R1, R2, R3, R4,
and R5.)
R2
I
R1
R3
+
+
9V
4V
R4
R5
4) Apply Kirchhoff’s current law (KCL) at the node labeled V3 in the following circuit. That is, write an
expression that sums the currents entering or leaving that node. (Unknown currents should be
expressed in terms of voltages and resistances. Use known values to simplify your expression as
much as possible.)
R2
V2
R4
V3
R1
3V
R3
V1
20mA
5) Find V1, V2, and V3 in the following circuit.
150Ω
V1
250Ω
V2
900Ω
750Ω
+
12V
600Ω
V3
300Ω
6) Determine how much power is dissipated in the 2kΩ resistor in the following circuit.
2kΩ
6kΩ
3.5kΩ
1.2kΩ
10mA
2.8kΩ
3kΩ
4.5kΩ