Students want to compare wave speeds on the same stretched string at two different tensions. They have a vibration generator, signal generator, pulley, masses, metre rule, a high-speed camera with a short exposure and an absorbing termination that suppresses reflected waves before the pulley. The camera resolves individual travelling-wave crests.
Plan a valid comparison using measurements of frequency and wavelength.
[6 marks]
6 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A region can add a nuclear plant or a gas-fired plant. It needs steady electricity for many years and aims to reduce carbon dioxide emissions. The nuclear plant costs more to build and produces radioactive waste.
Evaluate the two choices against the region's aims. Give a supported recommendation.
[6 marks]
6 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
A student says: "A stationary pair of magnets pushes apart, so momentum has been created. Two carts then collide and stick together, so momentum is destroyed." Both events occur on horizontal low-friction tracks.
Evaluate these two claims using momentum and energy, stating the system you consider.
[6 marks]
5 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
An imaging leaflet gives typical effective doses: one chest X-ray 0.020 mSv and one CT examination 4.0 mSv. These values are supplied; you do not need to recall dose units.
.1
Calculate the number of chest X-rays giving the same listed total dose as one CT examination.
[2 marks]
.2
Explain why the dose comparison alone cannot decide whether a patient should have the CT examination.
[3 marks]
6 marksHigher
Spec and skills
Original practice question
Answer and supported method checks
Two lamps provide the same useful light power of 9.0 W. Lamp A takes 60 W electrically; lamp B takes 12 W. Both are used for 300 s.
.1
Calculate the efficiency of lamp B as a percentage.
[2 marks]
.2
Calculate how much less energy lamp B takes from the supply in 300 s.
[2 marks]
.3
Explain why the smaller input does not make lamp B dimmer in this comparison.
