EE 40
Homework #1
Due February 4, 2003
Problem 1: 6 Points Possible
Prof. Ross’s lovely blue Honda Civic has a dead battery. A passerby offers to recharge her
battery using his car battery. Unfortunately, he is one of the thousands of people in the Bay
area driving an identical Honda Civic, and once the cars are hooked up, Prof. Ross cannot tell
which car is hers!
Luckily, she carries a digital multimeter wherever she goes, and determines that a 300 mA
current is flowing as shown between the 14 V batteries.
+
_
A
14 V
14 V
+
_
B
300 mA
a) Draw a circuit diagram showing how the multimeter is attached to measure current.
b) Which car belongs to Prof. Ross (which battery is being charged)? Justify your answer.
c) How much power is Prof. Ross’s battery absorbing?
Problem 2: 6 Points Possible
For each of the circuits below, determine whether the circuit violates any physical laws, and
state the violation. In addition, state whether there are any undetermined voltages or currents.
a)
10 V
-1 A
-5 V
1A
2A
-5 V
b)
2A
-3 A
-5 V
5A
12 V
Problem 3: 8 Points Possible
Find the voltages:
a

b
+
|

1.5 V
c
d

| +
+
3.5 V
|
9V
ground
a) Vba
b) Vad
c) Vd
d) Vc
Problem 4: 10 Points Possible
Determine the power absorbed by each element in this circuit.
2
2A
5
12 V
6V
