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Which of these symbols is used to represent a thermistor in an electrical circuit? A B C D (b) A student investigates how the current in a lamp changes with the potential difference across the lamp - Edexcel - GCSE Physics - Question 3 - 2019 - Paper 1
Question 3
Which of these symbols is used to represent a thermistor in an electrical circuit? A B C D (b) A student investigates how the current in a lamp changes with the po... show full transcript
Worked Solution & Example Answer:Which of these symbols is used to represent a thermistor in an electrical circuit? A B C D (b) A student investigates how the current in a lamp changes with the potential difference across the lamp - Edexcel - GCSE Physics - Question 3 - 2019 - Paper 1
Step 1
Calculate the missing resistance value for 2.0 V
Answer
To find the missing resistance values for the current of 0.14 A when the potential difference is 2.0 V, use Ohm’s Law, which states that resistance (R) is equal to the potential difference (V) divided by the current (I):
Substituting the values:
The calculated value rounds to approximately 14 Ω.
Step 2
Discuss the relationship between resistance and potential difference
Answer
The investigation indicates that resistance increases with potential difference, reflecting that as the voltage applied to the lamp increases, the resistance value also tends to increase. However, it is crucial to note that doubling the potential difference does not necessarily result in a doubling of the resistance. This is evidenced by the data in Figure 5, as the increases in potential difference do not match equal increments in resistance, highlighting the non-linear relationship.