A 40% lamp-power reduction sounds simple. It becomes harder when somebody calls it a guaranteed 40% reduction in a school’s entire electricity bill. Physics, Mathematics and English each give us a different tool for deciding what the evidence supports. This worked learner’s guide shows how to use those tools together without confusing calculation, experiment and public claims.
We will examine a fictional school corridor proposal, calculate the conditional result, identify missing evidence, and practise answering subject-specific questions. The goal is thoughtful G3 SEC examination performance, not installation advice.
- Distinguish watts, kilowatt-hours and dollars.
- Compare like with like and state the denominator.
- Separate rated figures, modelled results and observed measurements.
- Write a short, accurate public notice without making guarantees.
- Transfer the reasoning back to the correct SEC paper.
The decision that three subjects must explain differently
A school is considering replacing corridor lamps. The facilities team wants to know whether the electrical equipment will work safely and appropriately, the mathematics group wants to estimate energy savings, and the student council wants to explain the proposal clearly. These are related problems, but they are not the same problem. A correct calculation does not prove that a proposed fitting is suitable. A clear announcement does not make its data true. A safe installation does not by itself prove a particular annual saving.
This fourth volume in the lighting case brings together the earlier work: Physics circuits in Volume 1009, energy and tariff mathematics in Volume 1010, and English comprehension of claims in Volume 1011. Each retains its own examination standards. The purpose of the combined exercise is to develop transfer: use information from more than one subject, then return to the correct method of answering the question you are actually given.
For a learner, the panel is a model for checking reasoning. It is not a real school committee or an instruction to handle electrical systems. All figures and dialogue are fictional educational examples. Electrical installations, product selection and safety decisions belong to qualified professionals and the school authorities. Students can study data and wording without conducting live-circuit work or altering fittings.
Which SEC details are official and which belong only to this practice
The SEAB 2027 G3 school-candidate syllabus list, updated on 26 October 2026, gives the SEC codes K300 for English Language, K310 for Mathematics and K323 for Physics. The earlier O-Level reference codes are 1184, 4052 and 6091. The SEC replaces the previous O- and N-Level certificates from 2027 while retaining the underlying subject-level examination standards. A candidate sits subjects at their applicable G-level; “EMS” here describes an integrated learning exercise, not a separate examination subject.
The K300 English syllabus lists Writing (35%), Comprehension (35%), Listening (10%) and Oral Communication (20%). The K310 Mathematics syllabus specifies two papers of 90 marks each, each lasting two hours fifteen minutes and each contributing 50%; the final Paper 2 question applies mathematics to a real-world scenario. The K323 Physics syllabus specifies 40-mark multiple-choice Paper 1 (30%), 80-mark structured and free-response Paper 2 (50%), and 40-mark practical Paper 3 (20%). It makes practical planning, measurement, presentation and evaluation important.
The classroom panel itself is not an official examination component. It is a way to practise the forms of thinking that individual papers reward. The lesson for students is to recognise which discipline controls which answer: Physics justifies a physical statement; Mathematics shows operations and restrictions; English communicates the evidence faithfully to a defined audience.
The original case file: three sources, one proposal
Source A, equipment comparison: A team is told that 48 older corridor lamps have a stated rating of 20 W per lamp, while proposed replacements are rated at 12 W each. The proposal assumes the same number of lamps and an equal lighting schedule. No direct measurement of installed power or illumination is supplied. The team is not yet given a verified product lifetime, an installation quote or a maintenance plan.
Source B, classroom cost model: For the sole purpose of calculation, the school assumes that all lamps operate five hours per school day across 190 school days. The practice tariff is S$0.30 per kWh, deliberately invented rather than a statement of a Singapore rate. The panel is asked to estimate annual lamp-energy differences, not the school’s full bill. The energy model excludes installation, upkeep, electrical losses, taxes and other charges.
Source C, proposed public message: A draft states, “The new system guarantees every school a 40% electricity-bill saving. It is brighter, safer and ready to install immediately.” The draft is stronger than Sources A and B support. There is a defensible 40% rated-power comparison for the two types of lamp. There is no demonstrated 40% total-bill saving or proof of brightness, safety, suitability or immediate readiness.
The evidence panel must decide what can be said now, what can be calculated conditionally, and what must await proper investigation. It is an exercise in reasoning under a boundary, not in being cynical about a worthwhile proposal.
First separation: power is not energy
Power is a rate of energy transfer. A watt is a joule per second. Energy used over time depends on the power and the duration. A device with lower power may use less energy for the same running time, but the actual saving will depend on how it is used. That is why the two ratings cannot alone establish an annual bill amount.
The old total rated power is 48 × 20 W, which equals 960 W. The proposed total is 48 × 12 W, which equals 576 W. The difference is 384 W, or 0.384 kW. Relative to the old equipment total, the reduction is 384 divided by 960, which equals 0.4 or 40%. This is a conditional, specified comparison: it holds if the lamp count and rated conditions match those in the statement.
An easy mistake is to write “the school has reduced energy by 384 W”. That fails because W is the unit of power, not energy. A more accurate sentence is “The proposal reduces the total rated lamp power by 384 W.” The moment an annual figure is mentioned, the operating duration must enter. Physically consistent language is a form of good explanation, not merely a cosmetic use of units.
Second separation: the calculated estimate is not an observed result
Under the assumed schedule, the annual difference in energy is 0.384 kW × 5 hours per day × 190 days, giving 364.8 kWh. At the invented tariff of S$0.30 per kWh, the simplified annual lamp-energy charge difference is 364.8 × 0.30 = S$109.44. Each factor plays a different role. The lamp power contributes kilowatts, the schedule contributes hours, and the charge rate contributes dollars per unit of energy.
This estimate is internally consistent. It is not the same as measured annual savings. A real corridor could have variable use during examinations, holidays or evening activities. Controls might switch some fittings off. A proposed model might have a different installed power from its nameplate figure. School invoices may include components that the simplified classroom model ignores. The panel should not change a valid calculation to make it appear “more realistic” by guessing unprovided numbers.
A strong conclusion reads: “For 48 lamps operating under the same assumed schedule, the proposed 12 W lamps would use approximately 364.8 kWh less energy in 190 days than 20 W lamps. At the illustrative rate of S$0.30 per kWh, that corresponds to S$109.44 in modelled energy charges.” The words “assumed”, “would” and “modelled” protect the reader from mistaking an exercise for an invoice.
Third separation: component cost is not a completed purchasing decision
Imagine that someone adds an assumed installation price of S$640 to the case. Using only the simplified annual savings of S$109.44, the crude ratio 640 divided by 109.44 is about 5.85 years of the modelled school-use schedule. That is an arithmetic ratio, not an expert procurement payback forecast. It excludes replacement timing, maintenance, product specifications, future tariffs, different operating days and the value of suitable illumination.
To explain a break-even inequality, let y represent a number of equivalent operating years. Under the simplified model, 109.44y ≥ 640 gives y ≥ 5.85 approximately. If a question asks for the smallest whole number of full operating years satisfying this idealised comparison, the answer is six. If it asks when the system should actually be purchased, the inequality is not enough. Safety, maintenance, service life, budget and suitability matter.
This is a subtle but important transfer skill. A Mathematics paper may deliberately ask you to solve the model and interpret a whole-number condition. An English announcement should avoid making the six-year calculation sound like a guaranteed real-world recovery period. A Physics explanation must distinguish power, energy and components before making any conclusion. The same number may be handled differently because the questions ask different things.
An evidence ledger that prevents accidental overclaiming
An evidence ledger is a simple writing exercise with four columns in your notes: claim, source, condition and present status. For the power comparison, the claim is that rated lamp power is lower by 40%; its source is the stated 20 W and 12 W ratings, its conditions are an equal number of lamps and comparable rating assumptions, and its status is a supported comparison. For annual energy savings, the claim is 364.8 kWh; the source is arithmetic using the assumed school schedule, and its status is a model estimate.
For “the corridors will be brighter”, the evidence is insufficient because no suitable illumination measurement has been supplied. For “safer”, the evidence is insufficient because the proposed fittings have not been reviewed for electrical and operational suitability. For “total bills will fall by 40%”, the evidence is insufficient because the rating change concerns one category of equipment, not every electricity use and charge.
Do not allow labels such as “verified” or “unverified” to replace explanation. A good ledger identifies why a statement deserves its status and what would change it. For example, an actual comparison of consumption under controlled and documented usage conditions could improve confidence in the energy estimate, but it still would not prove an unchanged tariff or future usage. Evidence is rarely all-or-nothing; it is often conditional.
A genuine fair test is narrower than a dramatic demonstration
If a lesson asks how to compare two lighting products fairly, identify the variable deliberately changed and the quantities kept suitable for comparison. The changed variable may be the lamp model. Relevant controlled conditions include the operating duration and, where the question requires it, the measurement method and setting. If the outcome is electrical power, compare power readings appropriately. If the outcome is illumination, power alone is not an adequate substitute for a suitable assessment of light on the intended area.
This does not mean learners should perform tests on mains equipment. For real school installations, such testing requires competent staff and approved procedures. In a classroom, students can reason from provided safe low-voltage datasets or diagrams. They can also analyse a fictional table without touching any circuit at all. The Physics practical assessment rewards measurement, presentation, analysis and evaluation as well as planning; the skill is understanding reliable evidence, not adventurous handling of equipment.
A weak suggestion says “Keep everything the same.” That is too vague to assess. Better: “Compare the two products under a documented equal operating time, using the same suitable power measurement method, and keep all relevant measurement conditions consistent.” If the question is about visibility, name the need to check illumination separately. Different outcomes require different evidence.
What to do with a second source that disagrees
Suppose a trial report says the installed fittings used 620 W in the proposed configuration, not the total nominal 576 W. Do not erase either number. Ask what each measures. The 576 W is the sum of 48 stated product ratings. The 620 W may be a reading for a complete installation under a specified measurement boundary. Without further information, do not claim that the discrepancy is definitely an error or definitely due to one named component.
A careful panel would request the test conditions, measurement accuracy, total system boundary and equipment details. It would clarify whether both old and new arrangements were measured using comparable methods. Perhaps the added figure includes other components. Perhaps the rating was defined differently. The safe answer is that the sources are not necessarily directly comparable until the measurement definitions align.
A Mathematics exercise could ask you to calculate a new model estimate using 620 W, provided its assumptions are stated. A Science answer could explain which measurements need repeating or controls need improving. An English response could distinguish “rated total” from “measured installed input”. The ability to preserve a disagreement while investigating it is stronger than choosing the more convenient number.
A deliberately flawed comparison: changing the operating schedule
Consider two records. Old fittings are described as running six hours per day; proposed fittings are modelled at four hours per day. A total energy reduction calculated from these different schedules cannot be attributed wholly to the change in lamp rating. Some of it comes from operating the lights for fewer hours. If the aim is to isolate the effect of lamp power, use the same operating duration in both conditions.
There can be good practical reasons to revise operating hours. The error arises when a report combines changes and then claims the measured effect came entirely from one. In experimental design, this is confounding. A precise school report might say “The projected combined change in equipment and operating schedule lowers energy use in this model.” It should not claim “the new lamp alone caused the full reduction”.
The lesson generalises to many subjects. A Biology group might change light intensity and plant species together, then wrongly attribute a growth difference solely to illumination. A Mathematics group might compare populations with different denominators. An English writer might omit the changed condition and present an incomplete claim. An integrated learner recognises the shared reasoning problem while still applying the proper method to each subject.
A model table, and how to read it without a photograph
Imagine a plain-text table whose headings are Scenario, Lamp rating, Number of lamps, Hours per day, Days and Annual energy. Row A reads 20 W, 48, 5, 190, 912 kWh. Row B reads 12 W, 48, 5, 190, 547.2 kWh. Row C reads 12 W, 48, 4, 190, 437.76 kWh. These numbers follow from converting watts to kilowatts before multiplying by hours and days.
Comparing A with B isolates the rating change under the stated model. Comparing B with C isolates a schedule change for the proposed lamps. Comparing A with C gives the combined effect of both changes. The panel must choose the comparison that answers the question. It would be misleading to describe the full difference from A to C as a lamp-efficiency effect, because the daily duration changed too.
A strong examination explanation refers to the specific rows, describes what was held constant and identifies which conclusion the figures support. Avoid simply saying “C is best” without stating the criterion. C uses the least modelled energy, but the table cannot establish whether four hours a day provides suitable lighting for the corridor. Suitability is a separate condition that the table omits.
A reading of the supplier’s phrase “guaranteed win”
The wording “guaranteed win for every school” claims a level of certainty broader than the available figures. A reader may understand it to mean that installation is always beneficial, with no relevant trade-offs. Yet the case contains no full project price, suitability assessment or measured operating profile. The problem is therefore not simply that the phrase sounds enthusiastic; it creates an expectation that the evidence cannot yet justify.
In an English Paper 2 response, a student should explain that effect using the phrase and its implied universality. In a situational piece, the student council might replace it with “The proposed fittings have a lower stated power rating; the school is reviewing operating costs and suitability before any decision.” This wording is informative without being hostile to the idea.
The best public statements preserve a decision pathway. They explain what has been compared, which numbers are estimates, which matters remain under review, and what the audience can expect next. They do not need to burden readers with every calculation. They only need to avoid the omissions most likely to change the meaning of the claim.
An original panel hearing with four questions
Chair: “Can we announce that we will save exactly S$109.44 every year?” Mathematics representative: “Not as an observed fact. That figure follows the assumed 48 lamps, fixed five-hour schedule, 190 days and illustrative tariff. It is an estimate for lamp energy charges, not a verified full bill.”
Chair: “Can the lower wattage tell us the new corridor lighting is suitable?” Physics representative: “No. It supports a lower rated-power comparison. Suitable illumination and safe installation require separate checks. We should not let an energy figure stand in for them.”
Chair: “Why did the draft publicity message use ‘guaranteed’?” English representative: “It creates certainty and urgency. Since several conditions remain open, we should remove it or narrow the promise. A careful announcement can still say the proposal may reduce energy use.”
Chair: “What do we know now, and what happens next?” Recording secretary: “We can publish the nominal comparison and transparent model with clear qualifications. The facilities team should obtain qualified assessments and actual cost information. The school will decide only after reviewing evidence and constraints.”
This dialogue illustrates different expertise cooperating. No representative needs to pretend to know facts outside the case. The result is a more complete account, not an automatic yes or no to the proposal.
How to write a responsible public update
A draft public update could read: “Our school is reviewing a possible corridor lighting replacement. The proposed lamps are rated at 12 W rather than the 20 W rating of the older fittings, a 40% reduction in rated lamp power when compared under the same conditions. Using an assumed five hours per day on 190 school days, our classroom model projects about 365 kWh less annual lamp energy for 48 fittings. Actual outcomes and costs may differ. The school will check suitability, safety and installation arrangements before making a decision.”
This message is shorter than the full evidence ledger, yet it contains the right limitations. It avoids suggesting that students have authority over live electrical systems. It avoids presenting the fictional S$0.30 rate as a current tariff. It also avoids calling the lower-power product automatically “brighter” without appropriate evidence.
For English writing, identify purpose, audience and context before revising. Families need to understand the proposal; staff need to understand the stage of the decision; learners need to see a credible example of honest explanation. Precise and calm writing often communicates a worthwhile initiative more persuasively than slogans that cannot survive a simple question.
Three mini-examination tasks and model answers
Physics task: A question asks for the reduction in total stated power for 48 fittings, with the same operating conditions. Model answer: 48 × (20 − 12) = 384 W. State that this is a power difference, not an energy amount. If asked to explain a control, name the same number of fittings and comparable rating basis.
Mathematics task: Under five hours per day and 190 days, find the estimated annual energy difference. Model answer: 384 W = 0.384 kW; annual difference = 0.384 × 5 × 190 = 364.8 kWh. Essential working identifies the conversion and each factor. If told to give three significant figures, 365 kWh is the rounded result. Do not round before the calculation unnecessarily.
English task: Explain why the claim “40% less electricity cost for every school” is unsupported. Model answer: the 40% figure compares the rated power of the specified lamps, while actual school electricity costs depend on operating times, other electricity use and charges. The phrase “every school” also overlooks conditions and differences between institutions.
The same fictional source produces three different valid answers. The discipline lies in matching the question’s requirement to the right reasoning pathway.
Make the paper boundaries explicit
A Physics Paper 2 response may require a defined physical relationship, equation, explanation of variables, a sketch or an evaluation of experimental information. Marks are not awarded merely because the student writes “we need more evidence”. The learner must identify the relevant measurement, condition or physical principle. In a Mathematics paper, the model must show essential working, keep units consistent and interpret constraints. A correct numerical result with the wrong units can be misleading.
In English comprehension, an examiner assesses accurate understanding and explanation of what a writer means. A candidate should avoid importing a complicated formula if the question asks about tone or purpose. In situational writing, purpose and audience determine what belongs in the message and how claims should be qualified.
This boundary is especially helpful for students who are strong in one subject but less confident in another. A mathematically gifted learner can sometimes over-answer English with calculations. A fluent writer may substitute persuasive language for mathematical proof. A scientifically curious learner may offer extra hypotheses not supplied in a data question. Learn to value each strength while remaining disciplined about what the question asks.
An assessment of the decision, not merely the arithmetic
Suppose the panel is offered three choices: approve installation immediately, reject the idea permanently, or proceed to a defined review. The data supports neither an unconditional purchase nor a permanent rejection. It supports further investigation because the nominal power difference is real within the given comparison, but material questions remain about performance and total cost.
A thoughtful decision can state the criteria in advance: confirm the required lighting conditions, verify the proposed product and installation arrangements, collect comparable operational information, obtain cost estimates, and communicate the result without hiding uncertainty. That is not indecision. It is a sequence in which each step answers a question that matters to the final choice.
This approach helps with extended Mathematics real-world questions: a solution must respect the assumptions of the model and interpret what the feasible answer means. It helps with Science practical questions: design a test that isolates a relevant variable and explain limitations. It helps with English writing: avoid a promise that the available data cannot sustain. None of these skills is improved by adding impressive but unrelated details.
The danger of a second denominator
Percentages can be correct and still be incomparable. The rated-power reduction is 8 W per lamp measured relative to 20 W. If an advertisement later says “forty per cent better” but never defines the measured property or denominator, the panel cannot assume it refers to the same calculation. A percentage of energy, a percentage of the bill, a percentage of illumination and a percentage of purchase cost all have different meanings.
When answering, name the original quantity as well as the difference. “8 divided by 20” is meaningful because 20 W is the original rating. “8 divided by 12” asks a different question: how large the difference is relative to the proposed rating. Both are numbers that a calculator can produce, but the wording determines which ratio is valid.
For an English announcement, the best practice is to name both compared items. For Mathematics, show the denominator in working. For Physics, use the correct physical quantity and unit. This one small habit—state the base—prevents a surprising range of errors across the three disciplines.
Plan a safer data review without performing unsafe work
Students can examine supplied rating sheets and fictional datasets, draft questions for a facilities professional, or analyse historical switch-on logs that the school has permission to share. They should not open fittings, contact mains wiring, modify controllers or test installed electrical circuits. The educational aim is a sound scientific comparison and responsible communication, not hands-on electrical intervention.
For a hypothetical measurement review, the plan can identify the question: do the installations differ in total energy use under comparable operating schedules? It can identify the data: measured input energy under specified conditions, number of devices and duration. It can identify possible threats to comparison: mismatched equipment counts, different running hours, unrecorded controls or incomplete measurement boundaries. It can identify who is responsible for technical observations and who is merely interpreting the resulting data.
A good plan also anticipates what the data will not answer. Even an accurate one-week energy record may not demonstrate annual performance or product longevity. The report should distinguish the observation period from a projection. That habit of limiting conclusions is exactly what science education is meant to develop.
Extended case: an apparently better estimate turns out to be narrower
Imagine a second sheet states that the LED arrangement operated for 4.5 hours per day on average during a short review week. The first model assumed five hours. It is tempting to replace five hours with 4.5 for the entire year and call the new result more precise. That would be unjustified unless the short week represents the rest of the year. The better wording is that the additional observation suggests a different schedule during that particular week.
A student could calculate what the model predicts under a 4.5-hour assumption: 0.384 × 4.5 × 190 = 328.32 kWh. The arithmetic is straightforward. The inference is not. One week of observed running time does not establish 190 days of identical behaviour. If the panel uses the number, it must label the calculation as a scenario rather than proof.
This distinction also works in Biology. A few plants observed for three days may not reveal a season-long growth pattern. It works in public-health articles, travel information and everyday consumer advertising. A sample can improve understanding without authorising an unlimited conclusion. In exams, students who distinguish “if the assumptions hold” from “it certainly happened” show more mature interpretation.
A response to an objection from the audience
Audience member: “You have so many qualifications that the project sounds pointless. Why not just announce the forty per cent saving?” A constructive response is: “The figure is useful, but it describes the rated-power comparison for the specified lamps. We would rather explain that accurately and then assess the broader costs and suitability than promise a saving that may not match the actual project.”
This answer does not hide behind technical vocabulary. It acknowledges the audience’s wish for a simple message and gives a simple one. It also distinguishes caution from negativity. We can recognise potential benefits while being clear about what has and has not been demonstrated.
An English oral response could use this pattern: acknowledge the concern, state the key evidence, explain the limit, then propose the next sensible action. A Physics response would use measurements rather than persuasion. A Mathematics response would use the equations and constraints in the question. When students understand that a careful answer can still be decisive, they are less tempted to exaggerate in order to sound confident.
Independent panel challenge: decide which claims survive
Consider these statements. “The new fittings have a lower stated power rating.” “Annual savings have been measured at precisely 364.8 kWh.” “The school will save forty per cent on every electricity charge.” “The new lamps are guaranteed to be more suitable for every corridor.” “Using the stated schedule, the model predicts a reduction of 364.8 kWh in annual lamp energy.” “Technical suitability remains to be checked.”
Write supported, unsupported or conditional beside each, and give a reason. First is supported within the given rating comparison. Second is unsupported because the number was modelled, not measured. Third is unsupported because a lamp rating ratio cannot establish a reduction of every charge. Fourth is unsupported because the relevant suitability evidence was never supplied. Fifth is a supported conditional model statement. Sixth is a supported description of the review status.
Now rewrite each unsupported statement so it can be defended. For example, “The proposed lamps may reduce corridor lighting energy use under comparable conditions.” The exercise is not complete until the revised claim is still useful. “Something might happen” is too vague. Good qualification keeps the concrete information that the data supports and removes only what exceeds the evidence.
One-week practice plan for independent EMS transfer
On day one, rebuild the Physics explanation in words: what is power, why does time matter, and which measurements would be appropriate? On day two, complete the energy calculation without consulting the example, checking the conversion from W to kW. On day three, write the caveats as specific missing data, not as an empty phrase like “more testing required”.
On day four, examine the public claims and rewrite them for a parent or student audience. On day five, try the three mini-examination questions under time limits appropriate to short practice, without looking at the model answers. On day six, exchange the evidence ledger with a study partner: ask the partner to find one unsupported conclusion and one valid conditional inference. On day seven, complete an unseen transfer scenario such as water use or classroom cooling, but keep the same discipline of units, comparison base and source attribution.
Record the kinds of mistakes, not only the count. If you repeatedly confuse measured energy with estimated annual use, repair the modelling concept. If your calculations are correct but answers omit units, practise complete mathematical sentences. If your announcements exaggerate, work on attribution and qualifiers. A good revision route becomes narrower as the cause of each error becomes clearer.
Frequently asked questions
Is there an integrated EMS SEC paper? No. English, Mathematics and the relevant Science subjects have their own assessment requirements. This exercise is a learning route that connects them.
Must candidates know lighting procurement law? Not for this practice. It develops physical, numerical and language reasoning. Any real installation decision belongs to appropriate school and professional processes.
Does the percentage of energy saved always equal the percentage change in power? Only under the relevant equal-use assumptions. The example holds running time and lamp count constant. Change the schedule or the scope of the system and you must reconsider the comparison.
Should a student memorise the worked values? No. The numbers are fictional. Learn why units cancel, why the denominator matters, and why a result is conditional.
How can parents check useful progress? Ask the student to explain one number, one missing condition and one fair public sentence. An accurate three-part explanation is more useful than a long performance that hides uncertainty.
Can a student propose a real test? They can describe a fair comparison in writing and interpret safe supplied data. They should not alter installed electrical equipment or handle live circuits.
Route to the next subject and official sources
This finishes a four-volume lighting route. Read the preceding Physics, Mathematics and English lessons for detailed single-subject practice. For longer-term foundations use the Secondary English capability map, Secondary Mathematics capability map and the G3 SEC family guide. Learners crossing over from PSLE can revisit the PSLE Science result–conclusion–explanation route as an introduction to evidence boundaries.
The examination facts in this guide are drawn from the official 2027 SEAB G3 SEC school-candidate directory and the subject syllabuses: K300 English, K310 Mathematics and K323 Physics. These should be checked for the applicable examination year.
Next, our learning sequence shifts from electrical lighting to Biology. The question changes from energy consumed by lamps to how light intensity and other limiting factors may affect photosynthesis. A lower number on an energy meter is not the same thing as a biological response. It takes a fresh scientific model and a fair investigation to make that distinction.
