Download Unit 11 Electricity and Circuits Review 2014 ANSWER KEY

Unit 11
Electricity and Circuits Review
dih 2014
ANSWER KEY
__A___ 1) Which of the following resistors would have the highest current when it is correctly hooked up to
1.5 V battery?
A) 5  resistor
B) 10  resistor
C) 15  resistor
D) 25  resistor
___A___ 2) Three resistors, 4Ω, 6Ω, and 10Ω, are connected in parallel in an electric circuit. The
equivalence resistance is
A) Less than 4 Ω
B) between 4 Ω and 10 Ω
C) between 10 Ω and 20 Ω
D) 20 Ω
___B___ 3) As the number of resistors in a series circuit is increased, what happens to the equivalent
resistance and the total current in the circuit?
A) Equivalent resistance decreases and total current increases.
B) Equivalent resistance increases and total current decreases
C) Both equivalent resistance and total current increase.
D) Both equivalent resistance and total current decrease.
__A____ 4) As the number of resistors in a parallel circuit is increased, what happens to the equivalent
resistance and the total current in the circuit?
A) Equivalent resistance decreases and total current increases.
B) Equivalent resistance increases and total current decreases
C) Both equivalent resistance and total current increase.
D) Both equivalent resistance and total current decrease.
___B__ 5) Which circuit diagram below correctly shows the connection of ammeter A and voltmeter V to
measure the current through and potential difference across resistor R?
B
A
C
D
__D__ _ 6) A physics student is given three 10  resistors with instructions to create the circuit that would
have the lowest possible resistance.
A) series circuit with an equivalence resistance of 30 Ω
B) series circuit with an equivalence resistance of 3.3 Ω
C) parallel circuit with an equivalence resistance of 30 Ω
D) parallel circuit with an equivalence resistance of 3.3 Ω
__D___ 7) In which circuit would ammeter A show the greatest current?
A
B
C
D
Use the following circuit for the next eight
questions. Show your work.
__C___10) What is the equivalent resistance in
the circuit to the right?
A) .41 
B) 1 
C) 24 
D) 6 
VAB = 48V
___D__11) If the 8  resistor fails, what happens
to the 4  resistor?
A) It continues to be 4 .
B) It becomes 12 .
C) It becomes 16 .
D) The 4  resistor fails.
_C____12) What is the current in 8 Ω resistor?
A) 0.5 A
B) 1 A
C) 2 A
D) 4 A
__C___13) What is the power rating of 12 Ω
resistor?
A) 16 W
B) 32 W
C) 48 W
D) 96 W
__C___14) What is the total current for this
circuit?
A) 0.5 A
B) 1 A
C) 2 A
D) 4 A
__A__ 8) The number of current paths in this
circuit is
A) 1 path
B) 2 paths
C) 3 paths
D) 4 paths
__A___9) What is the voltage drop across the 4 Ω
resistor?
A) 8 V
B) 16 V
C) 24 V
D) 48 V
___C_ 15) What would happen to the total
current if a 6 Ω resistor was added in series to the
circuit?
A) Total current remains constant.
B) Total current would increase.
C) Total current would decrease.
D) Total current would drop to 0 A
----------------------------------------------------------------------------------------------------------------------------------Use following circuit for the next five questions.
___B__ 17) What is the current reading of the
ammeter?
A) 1.0 A B) .60 A
C) .40 A
D) .20 A
12V 
__D__ 18) What is the voltage drop across the 30
Ω resistor?
A) 2 V
B) 3 V
C) 6 V
D) 12 V
__A___19) What is the power of 30 Ω resistor?
A) 4.8 W
B) 12 W
C) 30 W
D) 75 W
__B___16) The equivalent resistance is
A) 10 Ω
B) 12 Ω
C) 25 Ω
D) 50 Ω
__A__ 20) What would happen to the 20 Ω
resistor if the 30 Ω resistor was removed from the
circuit?
A) It remains 20 .
B) It becomes 50 .
C) It becomes 10 .
D) The 20  resistor fails.
Use the following circuit for the next six questions. Show your work.
Vtotal = 48 V
R1 = 4 
___C___21) The number of current paths in this
circuit is
A) 1 path
B) 2 paths
C) 3 paths
D) 4 paths
__D____ 22) What is the voltage drop across R3?
A) 4 V
B)6v6 V
C) 12 V
D)48 V
___C__ 23) The total current flowing through this
circuit is
A) 6 A
B) 12 A
C) 22 A
D) 24 A
____A_____ 24) What is the power dissipated
across R2?
A) 192 W
B) 288 W
C) 576 W
D) 1056 W
R2 = 12Ω
I
R3 = 8 Ω
=
__A___ 25) Suppose another 6 Ω resistor is added
in parallel to this circuit, what happens to the
total current?
A) The total current would increase.
B) The total current would decrease.
C) The total current would stay constant
D) There is not enough information.
___C__ 26) Suppose another 6 Ω resistor is added
in parallel to this circuit, what happens to the
total voltage?
A) The total voltage would increase.
B) The total voltage would decrease.
C) The total voltage would stay constant.
D) There is not enough information.
------------------------------------------------------------------------------------------------------------------------------Use this circuit for the following next five questions
Vtotal = 33 V
Itotal = 1.5 A
__A_ 28) What is the current that passed across R2
(between C and D)?
A) 1.5 A
B) 2.8 A C) 18 A
D) 33 A
__C___ 27) What is the equivalent resistance for
this series circuit?
A) 4 Ω
B) 12 Ω
C) 22 Ω
D) 33 Ω
___B___ 29) What is the resistance of R2
(between C and D)?
A) 8 Ω
B) 10 Ω
C) 12 Ω
D) 16 Ω
_A____ 30) What is the voltage drop across 4 Ω
resistor?
A) 6 V
B) 12 V
C) 15 V
D) 33 V
__C___ 31) If the total voltage remains 33 V,
what will happen to the total current if you add a
6 Ω resistor in series?
A) Total current remains constant.
B) Total current will increase.
C) Total current will decrease.
D) Not enough information to determine.
In the electric circuit diagram below, possible locations of an ammeter and voltmeter are indicated by
circles 1,2, 3, 4.
Ammeter at 1 (in
series)
Voltmeter at 3 (in
parallel)
__B___ 32) Where should an ammeter be located to correctly measure the total current and where should a
voltmeter be located to correctly measure the total voltage?
A) ammeter at 1 and voltmeter at 2
C) ammeter at 2 and voltmeter at 3
B) ammeter at 1 and voltmeter at 3
D) ammeter at 3 and voltmeter at 4
__C___ 33) What is the approximate amount of electrical energy needed to operate a 1600 W toaster for 60
seconds?
A) 26.7 J
B) 1,600 J
C) 96,000 J
D) .0375 J
___C__ 34) How long are you texting on your 0.064 watt cell phone if you use 19.2 J?
A) 1.22s
B) 150 s
C) 300 s
D) 600 s
===================================================================================
Same
Add
Add Rec
V
I
R
1
120V
6A
20Ω
2
120V
4A
30Ω
10A
12Ω
Tot 120V
___B__ 35) Using the circuit diagram above, what would be the reading of ammeter A2?
A) 4.0 A
B) 6.0 A
C) 10 A
D) 20 A
__A___36) Using the circuit diagram above, what would be the reading of ammeter A3?
A) 4.0 A
B) 6.0 A
C) 10 A
D) 20 A
==================================================================================
Add
Same
Add
V
I
1
40 V
4A
10Ω
2
80 V
4A
20Ω
4A
30Ω
Tot 120 V
__B___ 37) Using the circuit diagram above, what is the current through the 20 Ω resistor?
A) 0.25 A
B) 4.0 A
C) 6.0 A
D) 12 A
R