DIDACTICS
MATERIALS
Didactic material 1: Classroom
rules:
To begin the activity we will watch a video that calls attention and
starts the brainstorming with questions about what we have watched.
We can ask questions such as:
How can we be a “good friend”?
What must we do to be supportive when working in groups?
Tell me several sentences to ask for help when you need it.
We will establish together a classroom rules (Our classroom rules) by “Brainstorming”. These are some examples:
Try to speak in
English always
Treat others as
you would like to be treated.
Respect other
people and their property.
Laugh with
anyone, but laugh at no one.
Be responsible
for your own learning.
Come to class and
hand in assignments on time.
Didactic material 2: Video for listening comprehension. Watch
the video and answer the following questions:
You will be able to answer these questions after seeing the video.
1. What happens to an atom if you pull off an electron from it?
A It explodes
B The atom then has a positive (+) charge
C The atom then has a negative (-) charge
D The atom acquires no charge and stays neutral
2. Which of the following will usually create static electricity?
A Rub a wet rag on a carpet
B Rub a coin on a carpet
C Rub your foot on a carpet
D Rub your hand on a door knob
3. What happens to a material that collects electrons on its surface?
A It gets negatively charged
B It gets positively charged
C It starts sparking continuously
D It stays neutral
4. What is the difference between a
spark and lightning?
A Lightning occurs in summer; sparks in winter
B Lightning is just a big spark
C Lightning makes noises but sparks do not
D Lightning is negatively charged, spark is
positively charged
5. How does friction between two
materials cause electrons to jump from one and
stick to another?
A Friction scrapes off electrons from one
material and deposits them on the other
material
B Friction doesn't move the electrons; adhesive
forces inside the material pull off the
electrons
C Friction moves electrons because the material
gets a net negative charge
D Friction arises because of charge imbalances,
which move electrons
6. Explain why for static
electricity to occur between two surfaces that are rubbed
against each other, one of the
materials has to be an insulator.
7. Why is the phenomenon of static
electricity observed more in dry, winter months
than in hot, humid summer months?
Didactic material 3: Fill in the gaps with the words in
the box.
First, watch the video and then fill in the gaps with the keywords
Conducting, particles, electricity, electrons,
repulsión, unbalanced, attraction,
protons
|
Matter is formed by atoms consisting of negatively
charged particles ………….. and positively
charged particles ……………. Between these particles,
there are forces of …………….or
…………….that generate a type of energy called…………….
In a balanced atom, the number of protons is equal to
the number of electrons. The
forces of attraction and repulsion between these ……………
are balanced. When this balance is
disturbed, the electrical forces become ……………and the
electrons are driven by their
electrical energy to other atoms in search of new
balances.
We call this transfer of charges electrical current
and it is produced in conducting materials.
……………materials transmit electrical energy across their surface.
Electric circuits allow us to use electricity as light or other forms of
energy (heat, sound or movement).
Didactic material 4:
Describing pictures
Look at the pictures below and discuss in pairs what you can see in each
one. At the end, individually, you have to form in your own notebook what is
the best definition or direct current and alternating current, with five
examples that you use in your daily life.
Sources for the activity:
http://physics10aps.blogspot.com.es/2013/09/ac-and-dc.html
http://www.explainthatstuff.com/electricity.html
http://www.buzzle.com/articles/understanding-the-difference-between-alternating-anddirect-
current.html
Didactic material 5: Roleplaying
In groups of three, read about each of the three main electrical
variables in a circuit:
voltage, current and
resistance.
-
The
number one of the group will be an expert in voltage.
-
The
number two of the group will be an expert in current.
-
The
number three of the group will be an expert in resistance.
Firstly, all the experts with the same number will meet up to talk about
what they have read in the text about their variable.
1. CURRENT
Current (I) is the variable that tells us how many
electrons flow through the cross-section of a conductor per unit of time. Its
unit of measurement in the International System is the ampere (A).
Electrons travel from the negative terminal of the power source to its
positive terminal (true direction). However, the direction of the
current is taken as the flow of the load from the positive terminal to the
negative
terminal (conventional direction).
2. VOLTAGE
Voltage (V) is the variable that tells us the
difference in electrical energy per unit of charge between two points in a
circuit. This difference can also be called the electric potential difference,
potential drop or electric tension.
Its unit of measurement in the International System is the volt (V).
3. RESISTANCE
Resistance (R) is the variable that tells us the
opposition to the passage of an electric current. Its unit of measurement in
the International System is the ohm (Ω).
In real life, all of the elements in a circuit have resistance. However,
in this unit we will consider the resistance of conductors and power sources to
be negligible.
Didactic
material 6: OHM’s
law
Listen to the video and
mark the sentences true (T) or false (F).
When we measure current, 6.24 bimillion electrons pass
through a point of the wire
According this video, an Ampere is a Coulomb per
second.
Current, Voltage and Resistance are related to one
another by Ohm’s law.
The positive and negative charges inside a battery are
created by the protons in the battery
Fill in the gaps with the
words in the box. Then, answer the question.
Difference, resistance,
directly, attraction, current,
inversely, conductor
|
Electrical energy is the energy generated by
the forces of…………..and repulsion between
charged particles. In an
electric circuit, electrical energy is generated when the electrons
move through the …………..due
to the potential ………….across the ends of the circuit.
Electrical power measures the energy that
is consumed by a load device or delivered by a
power source over a
certain period.
P= E/t= V x I
Ohm’s law states that the………..in a
circuit is………...proportional to the electric potential
difference impressed
across its ends and…………..proportional to the total………offered by
the external circuit.
I = V/R
With this equation, how we can calculate
the other variables by rearranging
the equation?
MATER
Didactic
material 7: Classify the following circuits with the help of the text below.
SERIES CIRCUIT
In a series circuit, the
resistors are connected one after the other, so all of the electrical
current flows through all of the load
devices. There is only one possible path for the current
to flow through. The calculation of
electrical variables is summarized in the table below,
where Rt, It, Vt and Pt refer to the variables of the
equivalent circuit.
PARALLEL CIRCUIT
In parallel circuits, load
devises are connected one different branches and the current is
split. There are several possible
paths for the current to flow through. More electrical current
flows in the branch that offers the
least resistance. The calculation of electrical variables is
summarized in the table below, where Rt, It, Vt and Pt refer to the
variables of the equivalent
circuit.
SERIES-PARALLEL COMBINATION CIRCUITS
In series-parallel combination
circuits, there are elements in series and elements in
parallel. To solve a series-parallel
combination circuit, we need to find out which resistors are in series and
which are in parallel. Then we can apply the equations for each case.
