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 simple motor has a rectangular current-carrying coil between two magnet poles. A student suggests increasing current, using stronger magnets and making the active sides parallel to the magnetic field to increase rotation.
Evaluate these suggestions using the motor effect. Explain the role of the two sides of the coil.
[6 marks]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A parachutist has reached a first terminal velocity before opening a parachute. Consider the motion from just before opening until a new terminal velocity is reached.
Explain the changes in resultant force, acceleration and speed throughout this sequence.
[6 marks]
6 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A manufacturer claims a rubber luggage strap is more suitable than a steel spring for repeated stretching under load. A fair comparison must use the same maximum applied force and check whether each sample returns to its original length.
Plan an investigation to compare how extension depends on force for the strap and spring, and test whether they recover their original lengths after repeated loading.
