Transcript In a series circuit

‘Current
and
voltage in
series
circuits’
L/O :- To understand how current and
voltage behave in a series circuit
‘Current and voltage in
series circuits’
L/O :- To understand how current and
voltage behave in a series circuit
Starter in back of books: True or false:
1. Static electricity is the build of protons on an insulating
material.
2. Like charges repel e.g. 2 negative electrons push each other
apart.
3. Static builds up when two conductors are rubbed against each
other.
4. Friction between any two insulating materials causes static
electricity.
5. Lightening happens when hot air rubs against cold air causing a
build up of static electricity.
Quick quiz- back of
your books:
• Name 2 things that can affect thinking distance when
stopping a car
• Name 2 things that can affect braking distance when
stopping a car
• What 2 things does your momentum depend on?
What can you say about these circuits
How can we remember the 2 types of circuit?
SERIES or PARALLEL
Hint: How do the episodes of a T.V. series go?
Each component comes one after another in a series.
Episode 1 then Episode 2 then episode 3
(never episode 1 at the same time as 2!)
1 then 2
in series
Hint: What does parallel mean?
Branches of a circuit are parallel to each other
Remember: the voltmeters have to measure the voltage
across the component, whereas the ammeter has to
measure the current between components
1
2
A2
v2
Information to write down
1. Voltage across cell
2. Voltage across bulb 1
3. Voltage across bulb 2
4. Current between cell and bulb 1
5. Current between bulb 1 and bulb 2
6. Current between Bulb 2 and cell
TASK
Look at the statements below. Your task is to find out
which of these is correct and to provide evidence to
support your answer
a)
b)
c)
d)
Current in a series circuit remains the same
Current in a series circuit is used up as it travels through
the components
Voltage is shared between the components in a series circuit
The voltage from the bulb is the same throughout a series
circuit
Assessment - You will be assessed on the evidence you
provide for your answer. You should create a table and use
the data to back up which statements you think are true
Remember: the voltmeters have to measure the voltage
across the component, whereas the ammeter has to
measure the current between components
1
2
A
v
Information to write down
1. Voltage across cell
2. Voltage across bulb 1
3. Voltage across bulb 2
4. Current between cell and bulb 1
5. Current between bulb 1 and bulb 2
6. Current between Bulb 2 and cell
Notes to take:
In a series circuit:
Voltage is shared between components.
Current is the same around each point of the circuit.
For example:
If a cell provides 10V and there are 2 identical bulbs in series,
then the voltage across each bulb would be 5V.
If the same cell provides a current of 3Amps, then the current
through each bulb will be 3 Amps.
Your evidence . . .
• Is your evidence repeatable? How do you
know?
• Is your evidence reproducible? How do you
know
• Is your data accurate? How do you know?
• Is your data precise? How do you know?
Accurate
Precise
Close to the true value
Close to the MEAN value
Using your rules, what would you expect to happen to
these components as the resistor was changed
a) ammeter
b) Voltmeter
c) A bulb
What have you learnt?
• Do you know the rules for current in a
circuit series
• Do you know the rules for voltage in a
circuit series?
• Can you explain why this happens
• Can you explain the difference between
repeatability and reproducibility?
• Can you explain the difference between
accurate and precise data