A student uses this circuit to investigate how the current in a filament lamp varies with the potential difference (voltage) across the lamp - Edexcel - GCSE Physics - Question 5 - 2016 - Paper 1
Question 5
A student uses this circuit to investigate how the current in a filament lamp varies with the potential difference (voltage) across the lamp.
(a) Add a voltmeter to... show full transcript
Worked Solution & Example Answer:A student uses this circuit to investigate how the current in a filament lamp varies with the potential difference (voltage) across the lamp - Edexcel - GCSE Physics - Question 5 - 2016 - Paper 1
Step 1
Adding a voltmeter to the circuit.
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Answer
To measure the potential difference across the lamp, the voltmeter should be connected in parallel with the lamp. This ensures that the voltmeter can accurately measure the voltage across the lamp.
Step 2
Complete the sentence by putting a cross (✗) in the box next to your answer.
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Answer
The correct answer is A: 12 joules per coulomb.
Step 3
When the variable resistor is at the halfway position, show that the resistance of the filament in the lamp is about 11 Ω.
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Answer
To find the resistance of the filament, we can use Ohm's Law, which states that voltage (V) equals current (I) times resistance (R), or V = IR.
Given that when the variable resistor is halfway, the voltmeter reads 4.0 V and the ammeter reads 0.37 A, we can rearrange the formula to find the resistance:
R=IV=0.37 A4.0 V≈10.81 Ω≈11 Ω.
Thus, the resistance of the filament in the lamp is approximately 11 Ω.
