9. (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 - Question 9 - 2019 - Paper 1

The student's conclusion is partially correct. From Figure 17, we can see that as the potential difference increases, the resistance indeed shows a trend of increasing values. However, the data suggests that the relationship is not perfectly linear, as the resistance values do not scale directly with the potential difference. For instance, the resistance at 1.0 V is not half of that at 2.0 V, indicating that resistance increases at a different rate as the potential difference changes.

Energy transfer begins at the battery, where a chemical reaction generates electrical energy, pushing charged particles (electrons) through the circuit. As electrons flow through the lamp's filament, they collide with the atoms in the filament, transferring energy to them. This increased atomic vibration causes the filament to heat up, resulting in light emission. The energy is thus transferred from the electrical energy in the battery to heat and light energy in the lamp, which is eventually dissipated into the surroundings.