A mains supply completes 150 full cycles in 3.0 s. A battery supply maintains its positive and negative terminals. Both supplies are connected separately to suitable lamps.
.1
Calculate the mains frequency.
[2 marks]
.2
Explain why both can transfer energy to a lamp even though the charge moves differently.
[2 marks]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A worker is near a sealed radioactive source for a short time. Another worker has radioactive dust on a glove. A supervisor recommends tongs, shielding and careful removal of the contaminated glove.
Explain the different hazards and how the precautions reduce them.
[6 marks]
6 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
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 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 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.
