A student measures the resistance of 0.20 m, 0.40 m and 0.60 m of one uniform wire. Values are 1.6 Ω, 3.2 Ω and 5.6 Ω. The 0.60 m measurement is made after current has flowed for several minutes.
.1
Use the first two results to calculate the expected resistance of 0.60 m of wire at the original temperature.
[2 marks]
.2
Evaluate the final result and suggest how to improve the investigation.
[3 marks]
4 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A heater supplies 12000 J to 0.10 kg of ice already at 0 °C. The specific latent heat of fusion is 334000 J/kg. Assume no energy reaches the surroundings.
.1
Calculate the mass of ice that melts.
[2 marks]
.2
Evaluate the statement that the final temperature must be above 0 °C because energy was supplied.
[2 marks]
6 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A town receives electricity from distant power stations through the National Grid. A pupil proposes removing all transformers because transformers do not create energy.
Evaluate the proposal by explaining the roles of the transformers and the cables.
[6 marks]
5 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A simplified early atomic model placed electrons inside a spread-out positive charge. Later scattering evidence supported a small positive nucleus. Further work showed that electrons occupy particular energy levels and that nuclei contain neutrons.
Evaluate the claim that changing the atomic model shows that scientific models are useless.
[5 marks]
5 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
Two proposed motion records describe a cart moving in one direction. Record A: velocity rises uniformly from 0 to 8 m/s in 4 s, then remains 8 m/s for 2 s. Record B: velocity remains 4 m/s for 6 s.
.1
Calculate how much farther the cart travels in record A than in record B.
[3 marks]
.2
Evaluate the statement: "Both records last six seconds, so their distances are equal."
