A student investigates the resistance of a lamp - Edexcel - GCSE Physics - Question 5 - 2016 - Paper 1
Question 5
A student investigates the resistance of a lamp.
She obtains these readings for the potential difference (voltage) across the lamp and the current in the lamp.
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Worked Solution & Example Answer:A student investigates the resistance of a lamp - Edexcel - GCSE Physics - Question 5 - 2016 - Paper 1
Step 1
Calculate the resistance, R, of the lamp.
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Answer
To find the resistance of the lamp, we use Ohm's law, which states that resistance ( R ) is equal to voltage ( V ) divided by current ( I ):
R=IV
Substituting in the given values:
R=0.40A6.0V
Calculating this yields:
R=15Ω
Step 2
Calculate the power supplied to the lamp.
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Answer
The power ( P ) supplied to the lamp can be calculated using the formula:
P=V×I
Substituting the known values:
P=6.0V×0.40A
Evaluating this gives:
P=2.4W
Step 3
Calculate the amount of energy transferred by the lamp in 40 s.
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Answer
The energy ( E ) transferred by the lamp can be calculated using the formula:
E=P×t
Where ( t ) is the time in seconds. Substituting in the power from part (ii) and the time: