Section 23.1
Simple Circuits
Practice Test
1.
A 60-Ω resistor and a 30-Ω resistor are in parallel. What is the equivalent resistance?
a.
20 Ω
b.
30 Ω
c.
90 Ω
d.
2 Ω
Hint
2.
Which pair of options below would result in a lower reading on
V
B
in Figure 23-4?
a.
decrease the battery voltage or increase
R
A
b.
decrease the battery voltage or decrease
R
B
c.
increase the battery voltage or decrease
R
B
d.
decrease the battery voltage or decrease
R
A
Hint
3.
What happens to lights in series if one goes out?
a.
they all go out
b.
they stay lit
c.
every other one goes out
d.
they flicker
Hint
4.
The equivalent resistance of resistors in parallel can be calculated by __________.
a.
R
= 1/
R
A
+ 1/
R
B
+ 1/
R
C
…
b.
R
=
R
A
+
R
B
+
R
C
…
c.
1/
R
= 1/
R
A
+ 1/
R
B
+ 1/
R
C
…
d.
1/
R
= 1/
R
A
x 1/
R
B
x 1/
R
C
…
Hint
5.
In the river model for an electric circuit, the amount of water flowing through the river each second is the __________.
a.
power
b.
current
c.
voltage
d.
path
Hint
6.
In Figure 23-3, if a third resistor were added to the circuit between the bottom ammeter and the battery, how would the reading on the top ammeter change, if at all?
a.
It would increase.
b.
This cannot be determined without knowing the value of the new resistor.
c.
It wouldn't change.
d.
It would decrease.
Hint
7.
Five lights of equal resistance connected in series will __________.
a.
never light up.
b.
flicker.
c.
be equally bright.
d.
be brighter the closer they get to the positive end.
Hint
8.
What is the equation to find current in a series of three resistors?
a.
I
=
V
/(
R
1
×
R
2
×
R
3
)
b.
I
=
V
(
R
1
×
R
2
×
R
3
)
c.
I
=
V
/(
R
1
+
R
2
+
R
3
)
d.
I
=
V
(
R
1
+
R
2
+
R
3
)
Hint
9.
A 1.5 V battery is attached to a 1.0-Ω resistor and a 2.0-Ω resistor in series. What is the current?
a.
0.50 A
b.
2.0 A
c.
4.5 A
d.
3.0 A
Hint
10.
A 340-Ω resistor and a 550-Ω reisistor are connected in parallel. This group is then connected in series with a 180-Ω and a 120-Ω resistors. What is the equivalent resistance of the circuit?
a.
510 Ω
b.
420 Ω
c.
550 Ω
d.
210 Ω
Hint
11.
Which pair of options below would result in a greater reading on
V
B
in Figure 23-4?
a.
decrease the battery voltage or decrease
R
A
b.
decrease the battery voltage or decrease
R
B
c.
increase the battery voltage or decrease
R
A
d.
increase the battery voltage or decrease
R
B
Hint
12.
If you have two lights in parallel and you add another identical light in parallel, what happens to the total current?
a.
It remains the same.
b.
It goes to zero.
c.
It increases.
d.
It decreases.
Hint
13.
What is the purpose of a voltage divider?
a.
to produce exactly twice the voltage of a lower-voltage battery
b.
to produce exactly half the voltage of a higher-voltage battery
c.
to produce a lower voltage from a higher-voltage battery
d.
to produce a higher voltage from a lower-voltage battery
Hint
14.
The __________ is the sum of all resistances in a series.
a.
equivalent resistance
b.
resistance total
c.
calculated resistance
d.
resistance
Hint
15.
A 20.0-Ω resistor and a 40.0-Ω resistor are connected in series to a 20.0-V battery. What is the voltage drop across the 40.0-Ω resistor?
a.
18.7 V
b.
13.3 V
c.
6.70 V
d.
30.0 V
Hint
16.
If another ammeter were placed immediately above the battery in the circuit of Figure 23-3, which ammeter(s) would it read the same as?
a.
all three
b.
the one on the right side
c.
the bottom one
d.
the top one
Hint
17.
A 45-Ω resistor and a 65-Ω resistor are connected in series. These resistors are then connected in parallel with a 120-Ω resistor. What is the equivalent resistance for the circuit?
a.
230 Ω
b.
57 Ω
c.
150 Ω
d.
22 Ω
Hint
18.
In Figure 23-3, if a third resistor were added to the circuit somewhere between resistors A and B, how would the reading on the bottom ammeter change, if at all?
a.
It would increase.
b.
This cannot be determined without knowing the value of the new resistor.
c.
It wouldn't change.
d.
It would decrease.
Hint
19.
If in Figure 23-6 resistor D were added in parallel to the other resistors, how would the voltages across resistors A and B be affected?
a.
A's would increase; B's would decrease.
b.
They would both remain the same.
c.
They would both decrease.
d.
They would both increase.
Hint
20.
Two 240.0-Ω resistors are connected in parallel and placed across a 12.0-V battery. What is the current in each branch of the circuit?
a.
0.100 A
b.
0.0250 A
c.
0.0500 A
d.
0.0125 A
Hint
21.
If you have a 90 V power source with a 30-Ω and 60-Ω resistor in series, what is the voltage drop over the 60-Ω resistor?
a.
2 V
b.
60 V
c.
30 V
d.
90 V
Hint
