STEM Quiz Competition · Private Senior High Schools · Ghana
Sample Questions
& Model Answers
Five rounds of progressively challenging STEM questions — from rapid-fire recall to integrated grand challenges. Click any answer to reveal it.
R1 · STEM Sprint
R2 · Think & Explain
R3 · Digital Response
R4 · Design & Innovate
R5 · Grand Challenge
Set 1 · Physics
High-Level Concept Traps
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Q1A body moves with constant speed in a circular path. What is the net force acting?AnswerCentripetal force
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Q2Increasing voltage while keeping resistance constant affects current how?AnswerIncreases
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Q3Work done is zero when force is perpendicular to displacement. Why?AnswerNo displacement in direction of force
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Q4A conductor offers resistance due to what fundamental cause?AnswerCollision of electrons
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Q5A system has 100% efficiency. What does this imply?AnswerNo energy loss
Set 2 · Mathematics
Precision & Logic Traps
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Q1If x² = 9, what is x?Answer±3
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Q2A function is linear if its graph is?AnswerStraight line
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Q3The sum of interior angles of a triangle is always what?Answer180°
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Q4If two ratios are equal, what is the relationship?AnswerProportion
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Q5If probability of event is 0, what does it mean?AnswerImpossible event
Set 3 · Chemistry
Misconception-Based Traps
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Q1A catalyst affects reaction rate by changing what?AnswerActivation energy
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Q2A strong acid differs from a weak acid in what way?AnswerDegree of ionization
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Q3Neutralization always produces what?AnswerSalt and water
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Q4Increase in temperature affects particles how?AnswerIncreases kinetic energy
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Q5An exothermic reaction releases what?AnswerHeat energy
Set 4 · Biology
Functional Misconceptions
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Q1Oxygen transport in blood is mainly by what?AnswerHaemoglobin
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Q2Photosynthesis occurs in which organelle?AnswerChloroplast
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Q3Diffusion occurs due to what driving factor?AnswerConcentration gradient
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Q4Enzymes are affected most by what factor?AnswerTemperature and pH
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Q5The main function of xylem is what?AnswerTransport of water
Set 5 · Agricultural Science
Application Traps
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Q1Continuous cropping leads primarily to what?AnswerNutrient depletion
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Q2Organic manure improves soil by what main property?AnswerStructure
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Q3Irrigation is most effective in which condition?AnswerLow rainfall
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Q4Crop rotation mainly controls what?AnswerSoil fertility and pests
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Q5Loamy soil is preferred because it has what property?AnswerBalanced drainage and retention
Set 1 · Physics
Energy System Failure Analysis
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Case StudyA solar lighting system works well during the day but fails to provide sufficient light throughout the night, despite receiving full sunlight exposure.
- Q1Identify the system limitation responsible for the failure.AnswerInsufficient energy storage
- Q2Determine the component that must be upgraded to extend lighting duration.AnswerBattery
- Q3Predict what will happen if resistance in the wiring increases.AnswerCurrent decreases
- Q4Identify the energy conversion that is not adequately sustained at night.AnswerChemical to electrical energy
- Q5Select the most effective improvement to ensure continuous lighting.AnswerIncrease battery capacity
Set 2 · Mathematics
Applied Cost & Optimization Analysis
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Case StudyA farmer wants to fence a rectangular plot of land measuring 30 m by 20 m using a limited budget.
- Q1Calculate the minimum fencing length required.Answer100 m
- Q2Determine the total cost if fencing is GH₵4 per metre.AnswerGH₵400
- Q3Identify the mathematical concept used in determining fencing length.AnswerPerimeter
- Q4Predict the effect on cost if the length is doubled and width unchanged.AnswerCost increases
- Q5Select the best strategy to reduce cost while maintaining area.AnswerUse a square shape
Set 3 · Chemistry
Soil Treatment Decision-Making
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Case StudyA soil sample with pH 4 is used for farming, resulting in poor crop yield despite adequate watering.
- Q1Identify the chemical condition affecting the soil.AnswerHigh acidity
- Q2Determine the most suitable substance to correct the condition.AnswerLime
- Q3Identify the chemical process involved in treatment.AnswerNeutralization
- Q4Predict the effect of leaving the soil untreated.AnswerReduced crop yield
- Q5Select the outcome expected after proper treatment.AnswerIncreased soil fertility
Set 4 · Biology
Health Risk Analysis
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Case StudyIn a densely populated area, poor ventilation leads to increased respiratory infections.
- Q1Identify the environmental factor contributing to disease spread.AnswerPoor ventilation
- Q2Determine the body system primarily affected.AnswerRespiratory system
- Q3Predict the effect of reduced oxygen supply to the body.AnswerReduced respiration efficiency
- Q4Identify the structure where gas exchange occurs.AnswerAlveoli
- Q5Select the most effective preventive measure.AnswerImprove ventilation
Set 5 · Agricultural Science
Sustainable Farming Analysis
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Case StudyA farmer repeatedly grows maize on the same land without applying fertilizers, leading to declining yields.
- Q1Identify the long-term effect on the soil.AnswerSoil nutrient depletion
- Q2Determine the farming practice responsible.AnswerContinuous cropping
- Q3Predict the effect on crop production over time.AnswerDecrease in yield
- Q4Select the most sustainable farming practice to correct the issue.AnswerCrop rotation
- Q5Identify the key benefit of applying the solution.AnswerImproved soil fertility
Questions Q1 – Q15
Mixed STEM · Digital Format
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- Q1A device operates at 12 V and 3 A. If resistance doubles, calculate the new current.Answer1.5 A
- Q2Identify the device that converts sunlight into electrical energy. [Picture identification]AnswerSolar panel
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Q3A solar system fails at night. What is the best improvement?AnswerB — Add battery storage
- Q4A rectangular field has area 120 m². If length doubles and width halves, find the new area.Answer120 m²
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Q5The graph shown represents what type of relationship? [Graph shown in Google Form]AnswerB — Direct
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Q6A farmer adds lime to acidic soil. What is the result?AnswerB — Soil becomes neutral
- Q7The image shows bubbles forming during a reaction. Identify the gas produced. [Image shown in Google Form]AnswerHydrogen
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Q8A person breathes faster at high altitude. Why?AnswerB — Less oxygen
- Q9Identify the structure where gas exchange occurs. [Image shown in Google Form]AnswerAlveoli
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Q10Crop yield increases after fertilizer use. Why?AnswerB — Increased nutrients
- Q11Identify the farming practice shown. [Image shown in Google Form]AnswerIrrigation
- Q12A machine uses 1000 J of energy with 50% efficiency. Calculate useful energy output.Answer500 J
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Q13A water filtration system fails to remove impurities. What is the likely issue?AnswerB — Incomplete filtration
- Q14Identify the process shown. [Image shown in Google Form]AnswerFiltration
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Q15A system improves efficiency using stored energy. What component is required?AnswerB — Battery
Set 1 · Physics
Electric Circuit Investigation
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ApparatusBattery, bulb, wires, resistor (or long wire), switch
Task
- Set up a simple circuit and observe bulb brightness.
- Introduce a longer wire/resistor and observe change.
- Record observations in a table.
- State the relationship between resistance and current.
- Explain the effect on brightness using electrical principles.
- Suggest one method to improve brightness without changing the battery.
Post-Experiment Questions
- Q1What observation confirms that current changed in your circuit?AnswerChange in brightness of bulb
- Q2Using Ohm's Law, explain why the bulb became dimmer.AnswerIncrease in resistance reduces current
- Q3Suggest one modification to reduce energy loss in the circuit.AnswerUse shorter/thicker wire
Set 2 · Chemistry
Reaction Rate Investigation
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ApparatusEffervescent tablets (whole & crushed), water, stopwatch
Task
- Place a whole tablet in water and record time taken to dissolve.
- Repeat with crushed tablet.
- Tabulate results.
- Compare reaction rates.
- Explain the difference using particle theory.
- State one factor controlled in the experiment.
- Suggest one industrial application of this principle.
Post-Experiment Questions
- Q1Which form of the tablet reacted faster based on your data?AnswerCrushed tablet
- Q2Explain the observed difference using collision theory.AnswerLarger surface area increases collision rate
- Q3Suggest one way to further increase the reaction rate.AnswerIncrease temperature
Set 3 · Biology
Respiration Investigation
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ApparatusStopwatch, student
Task
- Measure breathing rate at rest for 1 minute.
- Perform light exercise and measure again.
- Record results in a table.
- Compare the two values.
- Explain the difference using respiration concepts.
- State one limitation of the method.
- Suggest one improvement.
Post-Experiment Questions
- Q1What change did you observe after exercise?AnswerIncreased breathing rate
- Q2Explain why this change occurs in terms of energy demand.AnswerIncreased oxygen demand for respiration
- Q3Suggest one method to improve accuracy of your measurement.AnswerRepeat measurements and average
Set 4 · Mathematics
Data Modeling Investigation
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PatternA student records the following sequence: 2, 4, 6, 8, 10
Task
- Construct a table showing term number and value.
- Determine the rule governing the pattern.
- Express the rule algebraically.
- Calculate the 15th term.
- Verify your answer using substitution.
- State one real-life application of this pattern.
Post-Experiment Questions
- Q1What type of relationship exists in the pattern?AnswerLinear
- Q2How does the algebraic rule confirm your pattern?AnswerIt generates all terms correctly
- Q3Suggest one real-life system that follows this pattern.AnswerEqual spacing / fence posts
Set 5 · Agricultural Science
Soil Investigation
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ApparatusSandy soil, clay soil, water, containers
Task
- Add equal water to both soil samples.
- Observe and record drainage rate.
- Tabulate observations.
- Identify which soil drains faster.
- Explain results based on soil structure.
- State one agricultural implication.
- Suggest a method to improve water retention in sandy soil.
Post-Experiment Questions
- Q1Which soil showed faster drainage based on your results?AnswerSandy soil
- Q2Explain the difference using particle size and structure.AnswerLarger particles create bigger pores
- Q3Suggest one method to improve water retention in sandy soil.AnswerAdd organic matter
Questions 1 – 11
Constraint, Decision & Trade-off Analysis
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Q1Water Systems. A community uses two water sources: Borehole (1000 L/day, GH₵50, 90% reliability) and Rainwater tank (400 L/day, GH₵10, 60% reliability). Daily demand is 1200 L. The system must maintain at least 80% reliability. Select the best combination and give your reason.AnswerBorehole + Rain TankReasonMeets demand (1400 L) at lowest cost while maintaining acceptable reliability.
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Q2Waste Management. A student argues burning waste is best because it uses less energy. Burning processes 70% of waste but has high environmental risk; recycling processes 80% with moderate risk. Is the student's claim correct? Justify using the data.AnswerIncorrectReasonBurning has high environmental risk despite lower energy use, while recycling processes more waste with lower risk.
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Q3Food Security. Crop A: high yield, very high water use. Crop B: moderate yield, low water use, high pest resistance. Crop C: high yield, moderate water use, low resistance. Rank from most to least suitable under water scarcity and high pest infestation.AnswerB → C → AReasonCrop B minimizes water use and resists pests best.
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Q4Health & Sanitation. Dirty water is filtered but still causes disease outbreaks due to bacteria. State the correct sequence of treatment required and explain why this sequence is necessary.AnswerFiltration → Disinfection (chlorination/UV)ReasonFiltration removes particles; disinfection kills microorganisms.
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Q5Flooding & Drainage. Rainfall of 20 mm falls on a 30 m² surface, and 50% infiltrates the ground. Calculate the runoff volume and state the most effective surface modification to reduce flooding.AnswerRunoff = 300 L · Vegetated/permeable surfaceReasonIncreases infiltration and reduces runoff.
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Q6Transport & Infrastructure. Budget: GH₵5 million. Options: Gravel road (40 km/h, GH₵2M), Asphalt road (70 km/h, GH₵5M), Concrete road (60 km/h, GH₵7M). Select the best option and justify why another is not suitable.AnswerAsphalt roadReasonHighest speed within budget; concrete exceeds cost limit.
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Q7Climate & Environment. Budget: GH₵80/day. Select the best energy source and justify based on environmental and cost considerations.
Source Emission Cost (GH₵) Diesel 600 100 Solar 100 80 Grid 300 70 AnswerSolarReasonLowest emissions within budget. -
Q8Housing & Built Environment. A housing project cannot afford the most expensive insulation. Options: High heat loss & low cost / Medium heat loss & moderate cost / Low heat loss & high cost. Select the best option based on performance and cost trade-off.AnswerMedium heat loss (wood-type material)ReasonBalances thermal efficiency and affordability.
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Q9Digital Access. Budget: GH₵500. Option A: low speed, small coverage. Option B: high speed, exceeds budget. Option C: moderate speed, wide coverage. Select the best option and justify.AnswerOption CReasonBest coverage within budget.
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Q10Agriculture Systems. A farmer wants to maximize water efficiency but cannot afford the most expensive system. Select the most appropriate irrigation method.
Method Efficiency (%) Cost Flood 40 Low Sprinkler 65 Medium Drip 85 High AnswerSprinkler systemReasonHighest efficiency among affordable options. -
Q11Local Industry & Innovation. A factory must choose a machine avoiding high maintenance cost while maintaining high output and efficiency. Select the best machine and justify using all three factors (efficiency, output, maintenance).AnswerMachine CReasonHigh efficiency and output without high maintenance.