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2. (a) 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: Combined Science - Question 2 - 2019 - Paper 1
Question 2
2. (a) 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... show full transcript
Worked Solution & Example Answer:2. (a) 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: Combined Science - Question 2 - 2019 - Paper 1
Step 1
Which of these symbols is used to represent a thermistor in an electrical circuit?
Answer
The symbol used to represent a thermistor in an electrical circuit is commonly known as symbol D, which typically looks like a resistor with a circle around it, indicating its temperature-dependent resistance.
Step 2
One value of resistance is missing from the table in Figure 2. Calculate the value of resistance that is missing from the table.
Answer
To find the missing resistance value, we can use Ohm's Law, which states that resistance (R) is equal to the potential difference (V) divided by the current (I):
From the table,
- For a potential difference of 6.0 V and a current of 0.30 A, we can calculate the resistance:
The resistance values appear constant for increases in potential difference, reinforcing that the lamp behaves in a predictable manner, where the resistance does not double when the potential difference doubles.