Download electricity revision and questions 08

Year 10 Science Revision Booklet Questions
Hikohiko/Electricity in our homes 2015
Conductors
Insulators
Metals
Electrons
Cell
Battery
Bulb
Switch
Series
Parallel
Resistance
Ohms
Resistor
Volts
Watts
Fuse
Amps
Ammeter
Voltmeter
Energy
Power
Power pack
Key definitions to learn:
Current
Voltage (potential
difference)
Energy source
Energy user
Conductor
Insulator
Series circuit
Parallel circuit
Fuse
This is the flow of charge around a circuit. It can only flow if the
circuit is complete.
This is a measure of the energy given to each charge as it flows
through the circuit component.
A source of energy to drive electrons through a circuit e.g a
battery
A circuit component e.g. a lamp or resistor
A substance that conducts electricity e.g. copper wire, nichrome
wire, graphite. Some conductors are better than others.
A substance that is a poor conductor of electricity e.g. plastic,
rubber, wood.
The current flows from one component to the next , all
components are on the same pathway. The current is the same
at any point in a series circuit
The current flows from the battery and splits up between two or
more pathways. The sum of the current in the branches is equal
to the total current flowing.
Fuses are a safety device. A fuse contains a small piece of high
resistance wire designed to melt and ‘break’ the circuit when
there is an excess of current due to device or circuit malfunction.
Key Learning Points:
Know your symbols:
Year 10 Science Revision Booklet Questions
Electrical Circuits
Electricity is the flow of electrons around a circuit. Circuits can be shown using
diagrams.
All circuits need an energy source (a cell) and an energy user (e.g. a lamp).
Rules for circuit diagram drawing:
 Use a sharp pencil and a ruler.
 Lines at the corners should be drawn at approximately 900.
 Use the correct symbols and the circuit needs switch.
 The circuit must start and finish at a cell
Note
For current to flow through the circuit the switch must be complete. So the switch
must be closed.
A
V
Ammeters measure current and are
connected “in series” with the energy
converter.
Ammeters measure current in Amps i.e
2.0A.
Voltmeters measure voltage (potential
difference) and are connected “in parallel”
across an energy converter or energy
producer.
Voltmeters measure voltage in volts i.e.
6.0V.
Year 10 Science Revision Booklet Questions
Series and Parallel Circuits
The wiring in series and parallel circuits is different:
Series Circuit
Parallel Circuit
The following wiring diagram show that when wired in a series and one bulb breaks
then the circuit (loop) is broken so there is no path for the current. The other bulb goes
out.
However when one bulb breaks there is still a complete circuit (loop) in a parallel
circuit. This is shown below.
Household electrical circuits use parallel circuits.
A series circuit has only one path
A parallel circuit has more than one path
Current in a series circuit is the same
Current in a parallel circuit is divided
at all points in the circuit
between the branches
Voltage in a series circuit is divided
Voltage in a parallel circuit equal in all
between the energy converters and adds branches to the total input voltage
up to the total input voltage
Advantage
Advantage:
-Easy to wire, only one path to follow.
-if one bulb goes out, the other bulbs
remain on.
Year 10 Science Revision Booklet Questions
Disadvantage:
-if one bulb goes out, all the bulbs go out.
-voltage is divided between components
(eg bulbs may be dim)
-voltage is same in each part, bulbs are
bright
Disadvantage
-can be complicated/difficult to wire
Resistance
Resistance is a measure of how difficult it is for current to flow through a component.
The resistance of a circuit is measured in Ohms, e.g 10 Ω
Fuses
Fuses are a safety device. A fuse contains a small piece of high resistance wire
designed to melt and break the circuit when there is an excess of current due to
device or circuit malfunction. Remember it is high current that causes electrocution
(not voltage).
Website URL for extra revision:
http://www.bbc.co.uk/schools/ks3bitesize/science/physics/electricity_intro.shtml
Year 10 Science Revision Booklet Questions
Revision Questions:
1. Draw symbols for: a lamp / voltmeter /ammeter / open switch / resistor / fuse /
cell / battery / powerpack (powersupply)
2. Name 4 rules used when drawing a circuit diagram.
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
3. Draw a circuit diagram for the following:

A cell, a bulb and an ammeter to measure the current though the bulb

A cell, a bulb and a voltmeter to measure the voltage across the bulb

A series circuit with 2 bulbs, a cell and an ammeter and a switch

A parallel circuit with 2 bulbs, a cell and 3 ammeters

A parallel circuit with 2 bulbs, 2 voltmeters, cell and a switch
Diagrams:
4. What happens in a series circuit if one bulb goes out?
……………………………………………………………………………………………..
5. What happens in a parallel circuit if one bulb goes out?
………………………………………………………………………………………………
6. Is the current the same at all points in a series circuit?
………………………………………………………………………………………………
7. Is the current the same at all points in a parallel circuit? Explain your answer.
………………………………………………………………………………………………
8. Is the voltage across 2 identical bulbs in a series circuit the same?
Year 10 Science Revision Booklet Questions
………………………………………………………………………………………………
9. Is the voltage across 2 identical bulbs in a parallel circuit the same?
…………………………………………………………………………………………….
10. What unit do you measure voltage in?
………………………………………………………………………………………………
11. What unit do you measure current in?
………………………………………………………………………………………………
12. Calculate power using the equation: power = voltage x current for a lamp
which has a current of 3 Amps through it and a voltage of 12 Volts across it.
(Power is measured in Watts).
………………………………………………………………………………………………
………………………………………………………………………………………………
……………………………………………………………………………………………..
Year 10 Science Revision Booklet Questions
Draw a mindmap for this unit:
Add to it, as you develop your learning.
Electricity
Well done you have completed another revision unit.
Now reflect on how you can improve further:
Which aspects of the unit do I need to revise more carefully?
Which aspects of the unit do I need help with?
How will I seek this help?