Figure 10 shows two different types of the same circuit component - Edexcel - GCSE Physics Combined Science - Question 5 - 2021 - Paper 1
Question 5
Figure 10 shows two different types of the same circuit component.
What is the name of this circuit component?
A diode
B light dependent resistor
C thermistor
D va... show full transcript
Worked Solution & Example Answer:Figure 10 shows two different types of the same circuit component - Edexcel - GCSE Physics Combined Science - Question 5 - 2021 - Paper 1
Step 1
What is the name of this circuit component?
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Answer
The circuit component is a thermistor, which is a type of resistor that changes its resistance with temperature.
Step 2
Which row in the table describes the way that ammeters and voltmeters should be connected with a component in a circuit?
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Answer
Ammeters should be connected in series, and voltmeters should be connected in parallel. Thus, the correct option is D.
Step 3
Describe the relationship between the current and the voltage as shown in the graph in Figure 11.
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Answer
The relationship between the current and voltage in the graph is non-linear. As the voltage increases, the current also increases, but the rate of increase in current is not constant. This suggests that the filament lamp is exhibiting a characteristic of increasing resistance with increasing temperature as the current flows through it.
Step 4
Use the values of the voltage and current at point P and at point Q on the graph in Figure 11 to complete the table in Figure 12.
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Answer
voltage in V
current in mA
point P
2.0
point Q
4.5
Step 5
Calculate the resistance of the filament lamp when the voltage is 4.5V and the current is 51 mA.
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Answer
Using the formula for resistance:
R=IV
Substituting the values:
R=51×10−34.5
Calculating this gives:
R=88.2Ω
Step 6
Explain why the resistance of the filament lamp changes as the voltage across it increases.
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Answer
The resistance of the filament lamp changes with increasing voltage due to the phenomenon of thermal effects. As the voltage increases, the power dissipated in the filament increases, leading to a rise in temperature. The higher temperature causes the metal atoms in the filament to vibrate more vigorously, resulting in more frequent collisions between electrons and atoms, which increases the resistance. Thus, a non-linear relationship is observed between voltage and current.
