Key Concepts of PhysicsEdexcel GCSE Physics: Topic test

20 questions, 54 marks

Edexcel GCSE Physics

Key Concepts of Physics topic test

Total 54 marks

Name

Class

Date

1
A radio engineer is testing a new satellite communications link. The transmitter produces a signal at a frequency of 2.4 gigahertz, and the satellite orbits at an altitude of 35 786 kilometres above the Earth's surface.
(a)
What is the transmitter frequency in hertz, expressed in standard form?
[1 mark]
A2.4 × 10⁹ Hz
B2.4 × 10⁶ Hz
C2.4 × 10¹² Hz
D24 × 10⁸ Hz
(b)
What is the satellite's orbital altitude in metres, expressed in standard form to 3 significant figures?
[1 mark]
A3.58 × 10⁴ m
B3.58 × 10⁷ m
C3.58 × 10¹⁰ m
D3.58 × 10⁶ m
(c)
The engineer wants to express the satellite's altitude to 3 significant figures without using standard form. State this value in kilometres, and explain why significant figures are useful when reporting a measured quantity like this.
[2 marks]
Total for question 1: 4 marks
2
An electricity company operates a gas power station that generates electrical power at a steady rate of 1.8 gigawatts. A small fault causes the station's output breaker to trip and reset after a delay of 450 microseconds.
(a)
What is the power station's output in watts, expressed in standard form?
[1 mark]
A1.8 × 10⁶ W
B1.8 × 10¹² W
C1.8 × 10⁹ W
D1.8 × 10³ W
(b)
What is the breaker's reset delay in seconds, expressed in standard form?
[1 mark]
A4.5 × 10⁻⁷ s
B4.5 × 10⁻² s
C4.5 × 10⁴ s
D4.5 × 10⁻⁴ s
(c)
Convert the breaker's reset delay into milliseconds, and state how many gigawatt-hours of energy the station would supply in one hour of continuous operation at this power output, as a decimal (not standard form).
[2 marks]
Total for question 2: 4 marks
3
A quantity surveyor calculates the material needed for a bridge component. The steel beam supplied has a mass of 2350 kilograms, recorded by the yard's weighbridge to 3 significant figures, and its width and depth are measured with a tape measure as 240 millimetres and 180 millimetres, both to 2 significant figures.
(a)
Convert the beam's mass into tonnes (1 tonne = 1000 kg), giving your answer to 3 significant figures. Then explain what is meant by a measurement having been recorded 'to 2 significant figures', using the width measurement (240 mm) as your example.
[3 marks]
(b)
Calculate the beam's cross-sectional area in square metres, using the width and depth given above. Give your answer in standard form to 2 significant figures, and state one reason why giving more significant figures than this would be misleading.
[4 marks]
Total for question 3: 7 marks
4
A polar research team uses automated sensors to monitor conditions at a remote weather station. Over one recorded interval, the station measures a wind gust reaching 850 centimetres per second, and separately logs that a snow layer thickened by 3400 micrometres in one hour. The team must convert both readings into the SI base units of metres per second and metres before entering them into an international database that only accepts values in standard SI form.
(a)
Convert the wind gust speed (850 cm/s) and the hourly snow thickening (3400 micrometres) into their SI base units, showing your working. Then explain why expressing all readings in consistent SI units, rather than a mixture of cm/s and micrometres, is important when different research teams share data internationally.
[6 marks]
(b)
The team's database software stores every value to exactly 4 significant figures. Explain what problems could arise from forcing a value that was only ever measured to 2 significant figures, such as the wind gust originally read as 850 cm/s (8.5 × 10² cm/s), to be displayed as if it had 4 significant figures. Suggest one better way the software could handle values of differing precision.
[6 marks]
Total for question 4: 12 marks
5
A sports science lab times a 100 metre sprinter using an electronic starting gun linked to a timing gate. The system records the sprinter's race time as 9820 milliseconds, and measures the length of one of her strides using a motion sensor as 2100 millimetres.
(a)
What is the sprinter's race time in seconds?
[1 mark]
A9.82 s
B0.982 s
C98.2 s
D9820 s
(b)
What is the length of the sprinter's stride in metres?
[1 mark]
A21 m
B2.1 m
C0.21 m
D2100 m
(c)
Calculate the sprinter's average speed over the 100 m race, using her race time converted into seconds. Give your answer in metres per second to 3 significant figures.
[2 marks]
Total for question 5: 4 marks
6
A pharmaceutical manufacturer produces tablets containing a drug at a dose of 250 micrograms per tablet. A quality-control technician weighs a full production batch of 40 000 tablets on an industrial balance and records a total drug mass of 10.0 kilograms.
(a)
What is the stated dose of 250 micrograms expressed in kilograms, in standard form?
[1 mark]
A2.5 × 10⁻⁴ kg
B2.5 × 10⁷ kg
C2.5 × 10⁻⁷ kg
D2.5 × 10⁻¹⁰ kg
(b)
Using the technician's total batch mass (10.0 kg) and the number of tablets (40 000), what is the mass of drug per tablet in grams, in standard form?
[1 mark]
A2.5 × 10⁻⁴ g
B2.5 × 10² g
C4.0 × 10⁰ g
D2.5 × 10⁻¹ g
(c)
The technician's balance calculation (0.25 g per tablet) disagrees with the manufacturer's stated dose of 250 micrograms per tablet. Convert 250 micrograms into grams, and use this to state by what factor the technician's balance reading is too high.
[2 marks]
Total for question 6: 4 marks
7
A telecoms engineer is installing a new fibre-optic internet line. The connection is rated to transfer data at 940 megabits per second, and a single data packet takes 3.2 nanoseconds to travel along a 0.64 metre length of cable inside the router. A second, older cable in the same building is rated at 100 000 kilobits per second.
(a)
Express the data rate of the new fibre-optic line (940 megabits per second) in bits per second, using standard form. Then calculate the speed at which the packet travels along the 0.64 m cable, using the given time of 3.2 nanoseconds, giving your answer in metres per second to 2 significant figures.
[3 marks]
(b)
State the older cable's data rate (100 000 kilobits per second) in megabits per second, and in gigabits per second. Hence explain whether the older cable is faster or slower than the new fibre-optic line, and by roughly what factor.
[4 marks]
Total for question 7: 7 marks
8
An astronomy outreach team is preparing a public exhibit about the scale of the Solar System. They state that the average Earth–Sun distance is 149 600 000 kilometres, and that a beam of light takes 8.3 minutes to travel this distance. A separate exhibit panel describes the diameter of a dust grain found in a meteorite sample as 15 micrometres.
(a)
Convert the Earth–Sun distance (149 600 000 km) into metres, expressing your answer in standard form to 3 significant figures. Then convert the light travel time (8.3 minutes) into seconds. Explain why standard form is more practical than writing out the full distance in kilometres or metres on the exhibit panel.
[6 marks]
(b)
Convert the meteorite dust grain's diameter (15 micrometres) into metres, in standard form. Explain why standard form makes it easier to compare two quantities that differ by such a large number of orders of magnitude, such as the Earth–Sun distance (1.50 × 10¹¹ m) and the dust grain's diameter, compared with writing both numbers out in full or in mixed units (km and micrometres).
[6 marks]
Total for question 8: 12 marks

End of questions