Investigating parallel circuits
Experiment 6
Connect a cell to two lamps (in parallel) as shown in the diagram below. What
happens to the brightness of the lamp compared to experiment 1?
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A
B
Draw a circuit diagram for this experiment in the box below.
Compare the brightness of the two bulbs in the circuit. Is ‘A’ brighter than ‘B’? Is ‘B’
brighter than ‘A’? Are the two bulbs the same brightness?
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What happens if you disconnect one of the wires between bulbs ‘A’ and ‘B’?
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Experiment 7
Connect two cells to two lamps (in parallel) as shown in the diagram below. Compare
the brightness of the bulbs to the bulb brightness in experiment 6.
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Draw a circuit diagram for this experiment in the box below.
Fill in the gaps
In a ________________________ circuit there is only one possible path
for the current to follow. If a bulb blows the circuit is broken and the
_________________________ will stop flowing.
A _____________________ circuit contains branches that later join up
again. This means that the ________________________ can flow along
two or more possible paths in parallel circuits. If a bulb blows the current
can still flow through the other bulb and back to the _______________.
parallel
cell
Key words
current
series
current
Draw a series circuit diagram showing one
lamp wired to one cell.
Draw a series circuit diagram showing two
lamps wired to one cell.
What would happen to the brightness of the bulbs if more lamps were added to the
series circuit?
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Draw a parallel circuit diagram showing two
lamps wired to one cell.
Draw a parallel circuit diagram showing
three lamps wired to one cell.
What would happen to the brightness of the bulbs if more lamps were added to the
parallel circuit?
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