Use authentic IGCSE Physics questions and mark schemes to practise planning safe experiments, identifying apparatus, fixed points, variables and suitable measurements.
Fig. 4.1 shows a liquid-in-glass thermometer without a temperature scale. The liquid inside the thermometer has a melting point of −39∘C.
Describe simple experiments to mark the positions of the fixed points on this liquid-in-glass thermometer.
(place) in melting ice
when bead has stopped moving OR owtte mark as lower fixed point /0∘C
(place) in steam (above boiling water)
when bead has stopped moving OR owtte mark as upper fixed point 100∘C
State a design change that:
increases the sensitivity of a liquid-in-glass thermometer
thinner bore / tube OR smaller bulb OR use liquid which expands more (per unit change in temperature)
increases the range of a liquid-in-glass thermometer.
longer tube OR larger (volume) glass bulb OR use liquid which expands less (per unit change in temperature)