Download B2 6 mark question practice

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6 mark question practice
Electricity can be dangerous, if a fault occurs
in a circuit a shock could be fatal. Describe
two safety measures used in the UK to
reduce the risk of a fatal accident.
• Describe what a fuse does
• Describe what an Earth wire does
• Explain how each increases safety
Electricity can be dangerous, if a fault occurs in a circuit a
shock could be fatal. Describe two safety measures used in
the UK to reduce the risk of a fatal accident.
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A fuse is connected to the live wire
A fuse will melt if there is a fault causing too much current to flow
This causes the fuse to heat up and melt/break
This breaks the circuit and stops the current flowing
The fuse protects the user from shocks, fires and ‘blown’ appliances
• If a fault occurs that causes the live wire to touch the edge of an
appliance the user could get a shock
• The Earth wire is connected to the edge of an appliance
• If there is a fault the current will flow through the Earth wire to the
ground
• This prevents a current flowing through the user if they touch the
faulty device
Static electricity can be very useful when
used correctly. Explain how an object can
become charged and describe one use of
static electricity.
• Describe the role of electrons
• Explain how static electricity is used in:
– Paint spraying
– OR
– Smoke Precipitators
– OR
– Defibrillators
Static electricity can be very useful when used
correctly. Explain how an object can become
charged and describe one use of static electricity.
• When two insulators are rubbed together
they can become charged through friction
• Electrons move from one material to
another
• If an object gains electrons it becomes
negatively charged, if it loses electrons it
becomes positively charged
• spray gun charged
• paint particles charged the same so repel giving a fine spray
and coat
• object charged oppositely to paint so attracts paint into the
‘shadows’ of the object giving an even coat with less waste.
• High voltage metal grids put into chimneys to produce a
charge on the dust
• Dust particles gain or lose electrons
• Dust particles induce a charge on the earthed metal plate dust
particles are attracted to the plates.
• paddles charged
• good electrical contact with patient’s chest
• charge passed through patient to make heart contract
• care taken not to shock operator.
Explain how measurements from
radioactive carbon can be used to find
the date of old materials.
• What is radioactive carbon
• What happens to the amount of it when a
living thing dies
Explain how measurements from radioactive
carbon can be used to find the date of old
materials.
• Cosmic rays from the sun interact with the carbon dioxide in the
atmosphere to make Carbon-14
• Carbon-14 is a radioactive isotope that is unstable
• The unstable Carbon-14 will decay with a half life of 5700 years
• The amount of Carbon-14 in the air has not changed for thousands
of years
• When an object dies (e.g. wood) gaseous exchange with the air
stops, it no longer takes in carbon dioxide
• As the Carbon-14 in the wood decays the activity of the sample
decreases
• The ratio of current activity from living matter to the activity of the
sample is used to calculate the age within known limits.
A nuclear power station uses a fission
reaction to release energy. Describe a
nuclear fission reaction and explain how
the reaction is controlled in a power
station
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It starts with a neutron
Remember to state that energy is released
Describe a chain reaction
Describe the control rods
A nuclear power station uses a fission reaction to
release energy. Describe a nuclear fission reaction and
explain how the reaction is controlled in a power station
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Uranium nucleus hit by neutron
Causes nucleus to split
Energy released
2 more neutrons released.
When each uranium nucleus splits more than one
neutron is given out
• These neutrons can cause further uranium nuclei to split.
• Scientists stop nuclear reactions going out of control:
– rods placed in the reactor to absorb some of the neutrons
– allowing enough neutrons to remain to keep the process
operating.