Download Circuits and Circuit Elements

Name:______________________________Class:__________________ Date:__________________
Assessment
Circuits and Circuit Elements
Teacher Notes and Answers
18 Circuits and Circuit Elements
COMPLEX RESISTOR COMBINATIONS
1.
2.
3.
4.
5.
6.
7.
8.
9.
b
c
c
b
c
b
a
d
Student answers may vary. However, all
answers should include reducing the circuit
to smaller groups of series or parallel
combinations, calculating the equivalent
resistance of the groups, and finally the
resistance of the entire circuit. There is no
rule as to where to start or the order of the
steps to take.
10. 4.5 V
Given
Ra = 5.6 Rb = 8.2 Rc = 3.3 Rd = 7.5 Re = 4.7 Ic = 0.44 A
Solution
Find the equivalent resistance of Ra and Rb.
1
1
1
0.18 0.12
=
+
=
+
=
Rx
5.6 8.2 1 1
1
0.30
; Rx =
= 3.3
0.30
Find the equivalent resistance of Rc and Rd.
1
1
0.30
1
=
+
=
+
3.3 7.5 1 Ry
1
0.13 0.43
=
; Ry =
= 2.3 1
0.43
1
Find the equivalent resistance of the circuit.
Req = Rx +Ry + Re = 3.3 + 2.3 + 4.7 =
10.3 Use Ohm’s law to find the battery voltage.
V = Ic Req = 0.44 A 10.3 = 4.5 V
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
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Section Quizzes
Name:______________________________Class:__________________ Date:__________________
Assessment
Circuits and Circuit Elements
Section Quiz: Complex Resistor Combinations
Write the letter of the correct answer in the space provided.
_____ 1. You want to determine the current in a complex circuit. Which piece of
information will be least helpful in making your determination?
a. the equivalent resistance of the circuit
b. the number of devices in the circuit
c. the current in each element in the circuit
d. the voltage across each element in the circuit
_____ 2. You have three 100 resistors available. How would you connect
these three resistors to produce a 150 equivalent resistance? You
must use all of the resistors.
a. Connect all three resistors in parallel.
b. Connect all three resistors in series.
c. Connect one resistor in series with two resistors in parallel.
d. Connect two resistors in series with the third resistor in parallel to
the first two.
_____ 3. A circuit is constructed as follows: four resistors in parallel connected
in series with three resistors in parallel connected in series with two
resistors in parallel. All of the resistors have the same value. How does
the equivalent resistance of this circuit compare to the resistance of a
single resistor?
a. The equivalent resistance is less than a single resistor.
b. The equivalent resistance is the same as a single resistor.
c. The equivalent resistance is greater than a single resistor.
d. The equivalent resistance cannot be determined without the
resistance value of a single resistor.
_____ 4. Because household devices are connected in parallel in a circuit,
___________ as new devices are connected.
a. the current does not increase
b. the potential difference remains the same
c. the resistance of the circuit increases
d. the power dissipated in the circuit decreases
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
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Section Quizzes
Name:______________________________Class:__________________ Date:__________________
Circuits and Circuit Elements continued
_____ 5. In any complex resistance circuit, the current through any resistor in
the circuit is always
a. less than the total current through the circuit.
b. equal to the total circuit current.
c. less than or equal to the total circuit current.
d. less than or greater than the total circuit current.
_____ 6. In the circuit shown above, which resistors, if any, have equal voltages across them?
c. Ra, Rb, and Rc
a. Re and Rf
b. Ra and Rd
d. Rb, Re, and Rf
_____ 7. A circuit breaker is designed to limit the amount of __________ in a
circuit.
a. current
c. resistance
b. voltage
d. potential difference
_____ 8. Which of the following devices is always connected in series with a
household circuit?
a. air conditioner
c. lamp
b. electric range
d. fuse
9. Briefly describe how to find the equivalent resistance of a complex circuit.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
10. Five resistors are wired as shown in the figure above. If the current in the
4.7 resistor is 0.44 A, what is the terminal voltage of the battery?
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Physics
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Section Quizzes