RHSA SNC1D: Electricity
Name: ____________
Page___
WHAT IS VOLTAGE OR
POTENTIAL ENERGY DIFFERENCE?
A battery has chemical potential energy.
Energy (E) is measured in joules (J). Chemical
reactions in a battery energize and separate
electrons from atoms. The negative terminal of
the battery has excess energized electrons.
The positive terminal lacks electrons. When
the switch on a circuit is closed, the energized
electrons move from the negative terminal,
through a load and return to the positive
terminal without energy. The chemical energy
from the battery is converted to light energy.
RHSA SNC1D: Electricity
Name: ____________
Page___
Potential difference is the difference in
potential energy per coulomb of charge
between two points in the circuit. Potential
difference is also called voltage or electric
potential. Potential difference is measured in
volts by a voltmeter. The voltmeter must be
connected at the two points where the voltage
is being compared. That’s why voltmeters
must be connected in parallel.
The formula for potential difference is:
Potential Difference =
Energy
Electric Charge
OR
V
E
Q
RHSA SNC1D: Electricity
Variable
potential
difference or
voltage
energy
electric charge
Name: ____________
Variable
Unit
Symbol
V
volts
Page___
Unit
Symbol
V
E
joules
J
Q
coulomb
C
NOTE: Potential difference or voltage is the only
variable where the symbol for the units
is the same as the symbol for the
variable.
RHSA SNC1D: Electricity
Name: ____________
Page___
WHAT IS VOLTAGE OR POTENTIAL DIFFERENCE?
A battery has chemical potential energy. Energy (E) is measured in _____________________.
Chemical reactions in a battery energize and separate electrons from atoms. The __________
terminal of the battery produces _____________________________________________. The
______________________ terminal lacks electrons.
When the switch on a circuit is closed, the energized electrons move from the negative
terminal, through a _____________ and ________ to the positive terminal
___________________________________________________. The chemical energy from the
battery is converted to light energy.
Potential difference is _________________________________________________________
______________________________________________________________ .
Potential difference is also called _______________ or ________________________________.
Potential difference is measured in ________________ by a voltmeter.
The voltmeter must be connected at the two points where the voltage is being compared.
That’s why _____________ must be connected in _________________________. The formula
for potential difference is:
Potential Difference =
OR
V
E
Q
Variable
Variable Symbol
Unit
Unit
Symbol
Potential difference or
Voltage
Energy
Electric Charge
NOTE:
Potential difference or voltage is the only variable where the symbol for the units
is the same as the symbol for the variable.
RHSA SNC1D: Electricity
Name: ____________
Page___
Homework:
Read p 302 – 303
1. What is the purpose of electrons moving continuously around a circuit? (hint: think in terms
of energy carried by electrons)
2. Define the term “electric potential”. State the SI unit and name the symbol used for electric
potential.
3. Why is it possible to measure an electric potential across the terminals of a dry cell, even if
electrons are not flowing into the circuit?
4. Explain, in terms of the energy of the electrons, why someone would receive a severe
electric shock from a 120 V source, yet hardly notice the electric shock from a 6 V battery.
Extra: Electrochemical Cells, Wet Cells and Dry Cells
Read p. 306 – 307, do #1-3