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Guide sheet for Electricity Test.
Name
Voltage
Current
Resistance
Charge
Electrical Energy
Electric Power
time
Abbreviation
V
I
R
q
EE
P
t
Unit
Volt
Amp
Ohm
Coulomb
Joules
Watts
seconds
Unit Symbol
V
A

C
J
W
s
Equations:
I=V/R
Current
Voltage
Resistance
R=V/I
V=RI
P = IV
Series
The current is the same through
each resistor.
The current has only one path.
Voltages add up to the voltage of
the battery. The voltage is directly
proportional to the resistance.
Vs = V1 + V2
V~R
The effective resistance is the sum
of the individual resistances.
Re = R1 + R2
EE = IVt
Parallel
Currents add up to the current from
the battery. The current is inversely
proportional to the resistance.
Is = I1 + I2
I ~ 1/R
The battery voltage is the same as
the voltage across each resistor.
The more resistors put in parallel,
the less the overall resistance
becomes.
Electricity Test
Physics
name __________________
Multiple Choice.
1.)
Which of the following is the rate of flow of charge?
A.) voltage
B.) current
C.) resistance
D.) power
2.)
Which of these is the rate of energy transformed measured in Watts?
A.) voltage
B.) current
C.) resistance
D.) power
3.)
If the _____ of a circuit is increased, then the current will decrease.
A.) voltage
B.) current
C.) resistance
D.) power
1000
4.)
In the picture to the right, the currents in two of
the three ammeters are given. What must be the
current in the third ammeter.
A.) 200 mA
B.) 400 mA
C.) 800 mA
D.) 1200 mA
mA
200
mA
5.)
Which of the following is the negative charge carrier on the outside area of an atom?
A.) protons
B.) neutrons
C.) electrons
D.) nucleus
6.)
Suppose someone’s hair is neutral. If electrons are removed, then the hair will become
_____.
A.) conserved
B.) energy
C.) positively charged
D.) negatively charged
7.)
Among the following pairs of objects, which pair will attract each other?
A.) two protons
B.) two electrons
C.) two neutrons
D.) one proton and one electron
8.)
In which type of circuit is there only one path for the current to take?
A.) a series circuit
B.) a parallel circuit
9.)
A 9 V battery is connected to a wire whose resistance is 0.2 . The current in the
wire will be ____ . (see equation guide for help)
A.) 1.8 A
B.) 55.5 mA
C.) 45 A
D.) 555 mA
10.)
Two resistors are placed in parallel. If another one is added in parallel then the overall
resistance ____.
A.) goes down
B.) goes up
C.) makes all of the bulbs go out
D.) stays the same
11.)
Two resistors of the same resistance are placed in series. Their effective
resistance is 18 . The resistance of just one of these resistors can only be ____.
A.) 
B.) 
C.) 6 
D.) 3 
12.)
A 9 V battery ____ .
A.) gives 9 Joules of energy to every Coulomb of charge
B.) has a resistance of 9 Ohms
C.) has a current of 9 Amps which can be measured with an ammeter
D.) contains 9 J of energy
13.)
Suppose a circuit consists of a battery and a resistor whose resistance is 30 Ohms.
A current flows through the wire. If the voltage is doubled, then ____.
A.) the resistance will go from 30 to 60 Ohms
B.) the resistance will go from 30 to 15 Ohms
C.) the current will get cut in half
D.) the current will also double
14.)
In attempting to determine the resistance of a particular resistor, a student
measures and records a current of 10 A through a resistor when 16 Volts are
put across it. The resistance of the resistor is closest to ____ .
A.) 1600 
B.) 160 
C.) 16 
D.) 1.6 
15.)
A circuit is formed from a battery placed in series with a piece of wire that heats up when
an electric current passes through it. To achieve a higher power output, the following can
be done ____.
A.) turn up the current
B.) shorten the piece of wire (reduce its resistance)
C.) turn up the voltage
D.) actually, all of the above will increase the power
16.)
The power of a motor that draws 6 Amps when attached to a 12 V source is ____.
A.) 72 Watts
B.) 72 kWhr
C.) 0.5 Watts
D.) 2.0 Watts
17.)
How much energy that an appliance uses depends on _____.
A.) its voltage
B.) its current
C.) the time it is allowed to operate
D.) actually, the energy used would depend on all of these variables
18.)
If you had two 20  resistors, wiring them ____ would provide the least resistance.
A.) in series
B.) in parallel
19.)
Suppose a piece of nichrome wire is connected to a battery whose voltage may be varied.
Which of the following statements is FALSE?
A.) Increasing the voltage will increase the current
B.) Increasing the voltage will increase the power delivered to the wire.
C.) Decreasing the voltage will lower the amount of energy delivered to the wire
every second
D.) Decreasing the voltage will lower the resistance of the wire
20.)
Electric current is all of the following EXCEPT ______.
A.) current is measured in coulombs
B.) current may be measured in “Amps” or “Coulombs per second”
C.) current may be measured using an ammeter
D.) current is the flow of electric charge through a circuit
21.)
To measure current, one would use _____.
A.) a voltmeter
B.) an ammeter
22.)
The unit of charge which is equal to a large number of electrons (or protons) is a ______.
A.) Joule
B.) Coulomb
C.) Coulomb per second
D.) Watt
23.)
When we purchase energy from the electric company, we buy it in units of _____.
A.) Watts
B.) hours
C.) kilowatts
D.) kilowatt hours
24.)
Which of the following is the most efficient electric heater if each has a useful
output of 40 Watts?
A.) A heater that uses 10V and delivers a current of 5 A
B.) A heater that uses 12V and delivers a current of 5 A
C.) A heater that uses 15V and delivers a current of 10 A
A 120 Volt battery is connected in series with a 20  and a 40  light bulb (the bulbs
are drawn as resistors).
120 V
20 
25.)


40 
In the circuit above, what is the overall resistance?
A.) 
B.) 40 
C.) 20 
D.) 10 
5 
26.)
In the circuit above, what is the overall current?
A.) 3.0 A
B.) 2.0 A
C.) 1.5 A
D.) 1.0 A
E.) . 5 A
27.)
In the circuit above, which lightbulb, if either, will receive the larger current?
A.) the 40 and 20 lightbulb both get the same current
B.) the 20 lightbulb
C.) the 40 lightbulb

28.)


29.)
30).

In the circuit above, which lightbulb, if either, will receive the larger voltage across it?
A.) the 40 and 20 lightbulb both get the same voltage across them
B.) the 20 lightbulb
C.) the 40 lightbulb
Which of the following statements best describes what would happen when a bulb or
bulbs get unscrewed thus breaking the circuit at that point?
A.) both bulbs will go out if either the 40 or 20 light gets unscrewed
B.) if only the 40 light is unscrewed it will go out; the other will stay lit
C.) if only the 20 light is unscrewed it will go out; the other will stay lit
D.) none of these statements are true for the series circuit
Determine the voltage across each of the lightbulbs from the circuit at the top.
The voltage across the 40 Ohm bulb is ___. The voltage across the 20 Ohm bulb is ___.
A.) 60 V ; 60 V
B.) 120 V ; 120 V
C.) 40 V ; 80 V
D.) 80 V ; 40 V
A 45 Volt battery is connected in parallel with a 10  and a 30  lightbulb. The lightbulbs are
drawn as resistors.
Is
10 
30 
31.)

32.)

33.)


34.)
35.)
I1
I2
In this circuit above, what is the overall resistance?
A.) something greater than 30 
B.) something between 10 and 30 
C.) something less than 10 
In the circuit above, which lightbulb, if either, will receive the larger current?
A.) the 10 and 30 lightbulb both get the same current
B.) the 10 lightbulb
C.) the 30 lightbulb
In the circuit above, which lightbulb, if either, will receive the larger voltage across it?
A.) the 10 and 30 lightbulb both get the same voltage across them
B.) the 10 lightbulb
C.) the 30 lightbulb
Which of the following statements best describes what would happen if the 10 
lightbulb was unscrewed?
A.) both bulbs will go out
B.) only the 10 light will go out; the other will stay lit
C.) only the 30 light will go out; the other will stay lit
D.) none of these statements are true for the parallel circuit
Suppose ammeters were placed in three different spots in the circuit above.
Which of the following is the correct reading for these ammeters?
A.) Is : 3 Amps
I1 : 3 Amps
I2: 3 Amps
B.) Is : 6 Amps
I1 : 3 Amps
I2: 3 Amps
C.) Is : 6 Amps
I1 : 4.5 Amps
I2: 1.5 Amps
D.) Is : 6 Amps
I1 : 1.5 Amps
I2: 4.5 Amps
Problem: Determine the effective resistance of the circuit above. Write your response in
on the back of your answer sheet. Be sure to include the correct unit.