Potential Difference
EQUATION:
V
E
Q
1. Find the unknown quantity:
a) V =
W = 45 J
Q = 15 C
V = POTENTIAL DIFFERENCE in volts, V
E = ENERGY DIFFERENCE (WORK) in joules, J
Q = CHARGE in coulombs, C
b) V = 9 V
W=
Q = 150 C
c) V = 1.5 V
W = 225 J
Q=
WORD PROBLEMS
2. The potential difference between the two terminals on a battery is 9 volts.
How much work (energy) is required to transfer 10 coulombs of charge across the terminals?
3. Ten joules of work (energy) are required to transfer 2 coulombs of charge from X to Y.
What is the difference in potential between these two points?
4. It requires 600 joules of energy to transfer a quantity of charge between points C and D of a circuit, which
have a potential difference of 30 volts. How much charge is transferred?
5. Find the unknown quantity. CONVERT TO STANDARD UNITS (volts, joules, or coulombs) FIRST
a) V = 1000 mV = ______ V
W=
Q = 20 C
b) V =
W = 1.25 kJ = _________ J
Q = 1500 C
c) V = 1.21 GV =_________V
W=
Q = 2 000 000 C
Current Electricity
EQUATION:
I
Q
t
I = CURRENT in amperes, A
Q = CHARGE in coulombs, C
t = TIME is seconds, s
6. 3.00 C of charge pass a point in a wire in 3.0 ms. How much current is this?

7. 3.00 X 1012 electrons pass a point in a wire in 0.0060 seconds. What is the current in the wire in amperes?
8. How many electrons pass a point in a conductor in 1 second if the wireʼs current is 0.05 amperes?
Ohmʼs Law
EQUATION:
R
V
I
R = RESISTANCE in ohms, 
V = POTENTIAL DIFFERENCEin volts, V
I = CURRENT in amperes, A
9. The fuse
 for a car radio is a thin wire. The wire is made to burn apart is the current is too high?
What is the resistance of a fuse if it is to burn apart when 2.00 amperes pass through it at 240 volts?
10. A flash light bulb is labeled to uses 1.77 A. Its resistance is 1.60 Ω. What voltage is the light bulb rated for?
11. A 1.5 volt battery is has a wire connecting its positive side to its negative side. The battery draws 0.10
amperes of current. What is the resistance in the battery to create this current?