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]
4 marksFoundation and Higher
Spec and skills
Original practice question
Answer and supported method checks
A light pulse and a sound pulse leave the same device simultaneously. The observer is 680 m away. Take sound speed as 340 m/s and light speed as 3.0×108 m/s.
.1
Calculate the travel time of the sound.
[2 marks]
.2
Explain why timing from the visible flash to the sound is a reasonable way to measure the sound travel time here.
[2 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.
[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.
