Pearson Edexcel International GCSE in Physics · 4PH1 · Free · no account needed
Efficiency, Sankey Diagrams and Insulation — exam questions
11 original Incandio exam-style questions on Efficiency, Sankey Diagrams and Insulation, 27 marks, about 27 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for Efficiency, Sankey Diagrams and Insulation — the lesson that teaches it. Read the lesson first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
8 command words run through this set, and on Pearson Edexcel International GCSE Physics each one means something precise. Answering the wrong command is the commonest way a candidate who understands the lesson still loses the mark.
- State (1 mark)
- one precise fact or definition
- Which (1 mark)
- one option chosen from the set given
- Calculate (1–5 marks)
- select the equation, substitute, evaluate — and state the unit Misread as: giving a bare number with no equation and no unit
- Determine (1–4 marks)
- a value obtained by combining a reading or gradient with a relationship
- Describe (2–4 marks)
- developed, linked statements of what happens — including a named direction where one exists
- Explain (2–4 marks)
- the physics that causes it, set out as a line of reasoning Misread as: describing the change without giving the physical reason for it
- Suggest (1–3 marks)
- a plausible answer applying taught physics to an unfamiliar arrangement
- Identify (1–2 marks)
- the correct item selected from what is shown
Assessed on Paper 1 (4PH1/1P) and Paper 2 (4PH1/2P), against AO1, AO2, AO3.
Where these sit in the specification
Pearson Edexcel International GCSE Physics (4PH1) — statements 4.5 · 4.4 · 4.10. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 11 questions
Answer them on paper, then open the lesson's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
-
An electric winch motor is tested by using it to lift a load. The energy supplied to the motor and the energy transferred to the load are measured, and the rest is accounted for as thermal energy in the motor windings and as sound.
Table 1 — energy accounted for in one lift Where the energy goes Energy / J Supplied electrically to the motor 8000 To the gravitational store of the load 5200 To the thermal store of the windings 2600 To sound 200 (a)
(1)Identify
Identify the useful energy transfer made by the winch motor, using Table 1.
An electric winch motor is tested by using it to lift a load. The energy supplied to the motor and the energy transferred to the load are measured, and the rest is accounted for as thermal energy in the motor windings and as sound.
Table 1 — energy accounted for in one lift Where the energy goes Energy / J Supplied electrically to the motor 8000 To the gravitational store of the load 5200 To the thermal store of the windings 2600 To sound 200 (b)
(3)Calculate
Calculate the efficiency of the winch motor, using Table 1.
An electric winch motor is tested by using it to lift a load. The energy supplied to the motor and the energy transferred to the load are measured, and the rest is accounted for as thermal energy in the motor windings and as sound.
Table 1 — energy accounted for in one lift Where the energy goes Energy / J Supplied electrically to the motor 8000 To the gravitational store of the load 5200 To the thermal store of the windings 2600 To sound 200 efficiency of the winch motor = ............................ %
(c)
(3)Suggest
Suggest one change to the winch that would raise its efficiency, and explain why the change would work.
An electric winch motor is tested by using it to lift a load. The energy supplied to the motor and the energy transferred to the load are measured, and the rest is accounted for as thermal energy in the motor windings and as sound.
Table 1 — energy accounted for in one lift Where the energy goes Energy / J Supplied electrically to the motor 8000 To the gravitational store of the load 5200 To the thermal store of the windings 2600 To sound 200 (Total for Question 1 = 7 marks)
-
(1)State
State what happens to the energy a device does not transfer usefully.
(Total for Question 2 = 1 mark)
-
(1)Which
Which of these values could not be the efficiency of a real device?
Efficiency A 12% B 48% C 95% D 140% (Total for Question 3 = 1 mark)
-
(3)Calculate
A filament lamp is supplied with 150 J of energy and transfers 12 J as light. Calculate its efficiency.
efficiency = ............................ %
(Total for Question 4 = 3 marks)
-
(3)Determine
A kettle is 85% efficient and transfers 51 000 J usefully to the water. Determine the energy supplied to the kettle.
energy supplied to the kettle = ............................ J
(Total for Question 5 = 3 marks)
-
(3)Describe
Describe what a Sankey diagram shows about a device.
Figure 1 — a Sankey diagram (Total for Question 6 = 3 marks)
-
(4)Explain
Explain how laying insulation in a loft reduces the cost of heating a house.
(Total for Question 7 = 4 marks)
-
(3)Suggest
Suggest whether the householder is right to say the heater is the most efficient appliance they own.
An electric bar heater — An electric bar heater is designed to warm a room. Essentially all the electrical energy supplied to it ends up in the thermal store of the room. A householder points out that nothing is wasted and concludes that the heater must be the most efficient appliance in the house.
(Total for Question 8 = 3 marks)
-
(2)Explain
Explain why no machine can be 100% efficient.
(Total for Question 9 = 2 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 11 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain Efficiency, Sankey Diagrams and Insulation to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against James Watt over three rounds, marked against descriptors you can read first.
Completely free. No subscriptions, no paywalls, no account needed to start.
Back to the lesson
- Efficiency, Sankey Diagrams and Insulation — Working out what share of the energy did the job you wanted — and why the answer is never all of it.
- All of Incandio Physics · Incandio Exam Practice