5 questions · about 6% of the marks we indexed · examined in 5 of 5 sessions.
Questions by year
2026
2026 May/June · Paper 21 · Q3 (a(i), a(ii), a(iii), b(i), b(ii))7.8 marksCoal, oil and natural gas · Energy supply and demand · Solar, wind and other renewables
2025
2025 May/June · Paper 21 · Q3 (a(i), a(ii), b(i), b(ii), b(iii), b(iv), c(i), c(ii), d)15 marksCoal, oil and natural gas · Energy supply and demand · Solar, wind and other renewables · Thermal power
2024
2024 May/June · Paper 21 · Q1 (c(i), c(ii), c(iii))4.2 marksOfficial paper ↗Coal, oil and natural gas
2023
2023 May/June · Paper 21 · Q2 (c(i), c(ii), d)6.6 marksEnergy supply and demand · Hydel power
2022
2022 May/June · Paper 21 · Q3 (a(i), a(ii), a(iii), b(i), b(ii), b(iii), c, d)15 marksCoal, oil and natural gas · Energy supply and demand · Solar, wind and other renewables
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References only, not question text. Open Official paper ↗ where Cambridge publishes the paper,
or see the official Cambridge past-papers page; for other papers, ask your
school. “Paper 42” means Paper 4, variant 2.
Practice questions
Original questions written by HomiLabs in the style of the exam, with answers and mark schemes. They are not
Cambridge past paper questions and have not been reviewed by Cambridge. Try each one before opening the answer.
Q1Coal, oil and natural gas · Core · Paper 2 style · 5 marks
(a)Name the area in Sindh that has Pakistan's largest coal reserves.[1]
(b)Name the plateau in northern Punjab where oil has been produced for many years.[1]
(c)Name the gas field in Balochistan, discovered in 1952, that gave its name to Pakistan's piped gas.[1]
(d)State two uses of natural gas in Pakistan other than generating electricity.[2]
Show answer
(a) Thar (Thar coalfield, Tharparkar)
1 mark.
(b) Potwar Plateau
1 mark.
(c) Sui
1 mark.
(d) Cooking and heating in homes; making fertiliser (urea) in industry.
1 mark each for any two: domestic cooking/heating; fertiliser manufacture; industrial fuel (cement, textiles); CNG for vehicles.
Q2Coal, oil and natural gas · Core · Paper 2 style · 6 marks
(a)Describe the quality of most coal found in Pakistan.[2]
(b)Explain two problems of using Thar coal to generate electricity.[4]
Show answer
(a) Mostly low-grade lignite or sub-bituminous coal with a high content of moisture, ash and sulphur, so it gives less heat per tonne.
1 mark low grade/lignite; 1 mark high ash/sulphur/moisture or low heating value.
(b) The coal lies deep under thick sand, so huge amounts of overburden must be removed and water pumped out, making mining expensive. Burning lignite releases a lot of carbon dioxide, sulphur dioxide and ash, causing air pollution and health problems, and power plants need water in a desert area.
Two developed points: deep/under sand → costly mining; low quality → much coal per unit electricity; air pollution/greenhouse gases; water shortage in desert; remote → transmission lines needed; displacement of local people.
Q3Coal, oil and natural gas · Standard · Paper 2 style · 8 marks
Illustrative figures for natural gas in a country:Domestic production fell from 4.0 billion cubic feet per day (bcfd) to 3.2 bcfd over ten years. In the later year, demand was 6.0 bcfd.
(a)What is liquefied natural gas (LNG)?[1]
(b)Name the port where Pakistan's LNG import terminals are located.[1]
(c)Calculate the percentage fall in domestic gas production.[1]
(d)Calculate the percentage of demand met by domestic production in the later year. Give your answer to one decimal place.[1]
(e)Explain two disadvantages for Pakistan of depending on imported LNG to make up the shortfall in gas. You should develop your answer.[4]
Show answer
(a) Natural gas that has been cooled to a liquid (about −162 °C) so that it takes up much less space and can be carried by ship.
1 mark: natural gas cooled / turned into a liquid for transport.
(b) Port Qasim
1 mark: Port Qasim (Karachi).
(c) 20%
(4.0 − 3.2) ÷ 4.0 × 100 = 20%.
(d) 53.3%
3.2 ÷ 6.0 × 100 = 53.3%.
(e) LNG must be paid for in foreign currency, so large imports increase the trade deficit and put pressure on the rupee; world LNG prices rise and fall sharply, so when prices are high the government cannot afford enough cargoes and industry and homes suffer gas cuts.
1 mark for each of two reasons + 1 mark each for development (a consequence or 'which leads to'). Disadvantages: foreign exchange cost / trade deficit; price volatility; supply can be disrupted by events abroad; expensive terminals and pipelines needed; makes electricity and fertiliser more expensive.
Q4Coal, oil and natural gas · Standard · Paper 2 style · 6 marks
(a)Explain two reasons why Pakistan imports most of the oil it uses.[4]
(b)Suggest two effects on Pakistan's economy of a large rise in world oil prices.[2]
Show answer
(a) Pakistan's own oil fields in the Potwar Plateau and Sindh are small and produce only a small fraction of national demand. Demand keeps rising with the growing number of vehicles, industries and thermal power stations, so the gap must be filled with imports from countries such as Saudi Arabia and the UAE.
Two developed points: small reserves/low production; difficult exploration (cost, security); rising demand from transport, industry, power; refining capacity limited → also import petroleum products.
(b) The import bill rises, increasing the trade deficit and putting pressure on foreign exchange reserves; transport and electricity costs rise, causing inflation.
1 mark each for any two: higher import bill/trade deficit; currency falls/reserves drop; inflation; higher electricity tariffs; higher costs for industry and farmers.
Q5Coal, oil and natural gas · Standard · Paper 2 style · 7 marks
Illustrative data for a country's natural gas:Remaining reserves: 15 trillion cubic feetProduction per year: 1.2 trillion cubic feetDemand per year: 1.8 trillion cubic feet
(a)Calculate the number of years the reserves would last at the current rate of production, if no new gas is found.[2]
(b)Calculate the shortfall between demand and production each year.[1]
(c)Calculate the percentage of demand met by domestic production. Give your answer to one decimal place.[1]
(d)Describe how Pakistan has tried to meet the shortfall in gas supply.[3]
Show answer
(a) 12.5 years
M1 15 ÷ 1.2; A1 12.5 years.
(b) 0.6 trillion cubic feet
1.8 − 1.2 = 0.6.
(c) 66.7%
1.2 ÷ 1.8 × 100 = 66.7%.
(d) Importing liquefied natural gas (LNG), mainly from Qatar, through terminals at Port Qasim; exploring for new gas fields; reducing gas supply to some users such as CNG stations and industry in winter; planning pipelines from Iran and Turkmenistan (TAPI).
1 mark per point, max 3: LNG imports; LNG terminals at Port Qasim; supplier Qatar; new exploration; rationing/load management; proposed pipelines (Iran–Pakistan, TAPI).
Q6Coal, oil and natural gas · Standard · Paper 2 style · 6 marks
(a)Name two oil refineries in Pakistan and state where each is located.[2]
(b)Explain why some refineries are located at the coast and one is located inland in the Potwar region.[4]
Show answer
(a) Attock Refinery, near Rawalpindi; Pak-Arab Refinery (PARCO), at Mahmood Kot near Multan (also accept National Refinery or Pakistan Refinery in Karachi).
1 mark each correct refinery with location.
(b) Coastal refineries in Karachi are where imported crude oil arrives by tanker, so it can be refined without costly transport inland. The Attock refinery was built close to the Potwar oil fields to process local crude oil and serve northern markets.
2 marks coastal: imported crude arrives by sea/port facilities/market in Karachi; 2 marks inland: near local oilfields/raw material/northern markets; PARCO linked by pipeline (credit).
Q7Coal, oil and natural gas · Standard · Paper 2 style · 5 marks
(a)State two reasons why CNG became a popular fuel for cars and rickshaws in Pakistan.[2]
(b)Explain why many CNG stations have since closed or face supply cuts, especially in winter.[3]
Show answer
(a) It was cheaper than petrol; it produces less air pollution, and Pakistan had its own gas so it reduced oil imports.
1 mark each for any two: cheaper than petrol/diesel; local supply; cleaner; government encouraged it to cut oil imports.
(b) Domestic gas production has fallen while demand has grown, so there is not enough gas. In winter households need more gas for heating, and the government gives priority to homes and power stations, so CNG stations are cut off first; imported LNG is more expensive, so CNG is no longer much cheaper than petrol.
1 mark each, max 3: falling reserves/production; rising demand; winter heating demand; priority to domestic users/power; expensive LNG raises price; government policy restricting new connections.
Q8Coal, oil and natural gas · Challenge · Paper 2 style · 7 marks
(a)Explain why the gas pipeline network is densest in Punjab and Sindh.[3]
(b)Explain two reasons why Balochistan, where Sui is located, has had relatively little benefit from its own gas.[4]
Show answer
(a) Most of Pakistan's population, cities and industries are in Punjab and Sindh, creating the greatest demand; the land is mostly flat plains, which makes laying pipelines easier and cheaper; major gas fields (Sui, Qadirpur, Mari) lie in or near Sindh.
1 mark each, max 3: population density; industry/fertiliser plants; flat land; nearness to gas fields; power stations; cities like Karachi, Lahore, Faisalabad.
(b) The population is small and scattered over a huge area, so supplying gas to villages through pipelines is costly and uneconomic. Most gas was piped to industrial and urban centres elsewhere, and disputes over royalties and security problems have limited investment in local distribution.
Two developed points: scattered population/large area; high cost of distribution; gas sent to Punjab/Sindh industry; limited royalties/development spending; security problems; mountainous terrain.
Q9Coal, oil and natural gas · Challenge · Paper 2 style · 8 marks
Coal-fired generating capacity in a country (illustrative figures, MW):Plants using local coal 1,500Plants using imported coal 2,500Plants using a blend of local and imported coal 2,000Total 6,000
(a)Calculate the percentage of the total from imported coal. Give your answer to one decimal place.[1]
(b)Calculate how many more megawatts of plants using only local coal are needed for local-coal and imported-coal plants to have equal capacity, assuming imported-coal capacity stays the same.[1]
(c)Read the two views:View A: Pakistan should build more power stations that use Thar coal.View B: Pakistan should stop building coal-fired power stations.Which view do you agree with more? Give reasons for your answer, referring to both views.[6]
Show answer
(a) 41.7%
2,500 ÷ 6,000 × 100 = 41.7%.
(b) 1,000 MW
2,500 − 1,500 = 1,000 MW.
(c) A: huge local reserves, reduces import bill and dependence on foreign fuel, energy security, development and jobs in Tharparkar, steady base-load supply. B: lignite is polluting (CO₂, SO₂, ash), adds to climate change to which Pakistan is very vulnerable, needs scarce water, displaces communities, and solar/wind are now cheaper. Reasoned judgement.
Levels: L1 (1–2) simple; L2 (3–4) developed for one view; L3 (5–6) developed for both views with conclusion.
Q10Solar, wind and other renewables · Core · Paper 2 style · 4 marks
(a)Define the term 'renewable energy resource'.[1]
(b)Name two renewable sources of energy, other than hydel, that are used to generate electricity in Pakistan.[2]
(c)Name the area in Sindh where most of Pakistan's wind farms are located.[1]
Show answer
(a) A source of energy that is naturally replaced and will not run out when used, such as sunlight, wind or flowing water.
1 mark: replenished naturally / will not be used up.
(b) Solar and wind (also accept bagasse/biomass).
1 mark each for any two: solar; wind; bagasse/biomass; biogas.
(c) The Gharo–Keti Bandar wind corridor (around Jhimpir/Thatta)
1 mark Gharo–Keti Bandar corridor / Jhimpir / Thatta district.
Q11Solar, wind and other renewables · Core · Paper 2 style · 5 marks
(a)Describe how a solar panel system can provide electricity for a house in a village not connected to the national grid.[3]
(b)Give two reasons why much of Pakistan is suitable for solar power.[2]
Show answer
(a) Photovoltaic panels on the roof turn sunlight directly into electricity (direct current); it charges batteries so power can be used at night; an inverter changes it to alternating current for lights, fans and appliances.
1 mark per point, max 3: PV panels/cells; convert sunlight to electricity; battery storage for night; inverter; panels facing south/in sun; no grid connection needed.
(b) Most of the country has many hours of strong sunshine for most of the year; large areas of flat, unused desert land (e.g. Cholistan, Balochistan) are available for solar parks.
1 mark each for any two: high sunshine hours/clear skies; high intensity in low latitudes; deserts with little cloud; cheap flat land; dry climate.
Q12Solar, wind and other renewables · Core · Paper 2 style · 6 marks
(a)Explain two advantages of using biogas in rural areas of Pakistan.[4]
(b)State two reasons why biogas plants are not more widely used.[2]
Show answer
(a) Biogas from animal dung provides free fuel for cooking and lighting, so families save money and need not cut trees for firewood, reducing deforestation. The slurry left after gas production is a good fertiliser, improving crop yields.
Two developed points: cheap/free fuel → savings; reduces firewood use → less deforestation; cleaner than burning dung/wood → less indoor smoke, better health; slurry as fertiliser; uses waste/hygiene; saves women's time collecting fuel.
(b) Initial cost of building the digester is too high for poor farmers; a family needs several animals to supply enough dung every day.
1 mark each for any two: initial cost; need enough cattle/dung; lack of awareness/technical skill; maintenance; gas output falls in cold weather; water needed.
Q13Solar, wind and other renewables · Standard · Paper 2 style · 7 marks
A house in Multan has a rooftop solar system rated at 3 kW. On average it produces its full rated power for the equivalent of 4 hours a day (illustrative figures).
(a)Calculate the electricity generated by the system in one 30-day month.[2]
(b)Calculate the money saved in one month if grid electricity costs Rs 50 per kWh.[1]
(c)The system cost Rs 540,000. Calculate how many months it would take for the savings to repay this cost.[1]
(d)Explain why many households and businesses in Pakistani cities have installed rooftop solar panels in recent years.[3]
Show answer
(a) 360 kWh
M1 3 × 4 × 30; A1 360 kWh.
(b) Rs 18,000
360 × 50 = Rs 18,000.
(c) 30 months
540,000 ÷ 18,000 = 30.
(d) Grid electricity prices have risen sharply, so solar quickly pays for itself; load-shedding makes grid supply unreliable; panel prices have fallen greatly, and net metering lets owners sell extra power to the grid.
1 mark each, max 3: rising tariffs; load-shedding/unreliable supply; cheaper (imported) panels; net metering; abundant sunshine; reduces bills for businesses.
Q14Solar, wind and other renewables · Standard · Paper 2 style · 6 marks
(a)Explain two reasons why the coastal area of southern Sindh is suitable for wind farms.[4]
(b)State two disadvantages of wind power.[2]
Show answer
(a) Strong and steady winds blow from the sea, especially during the summer monsoon months, so turbines turn for many hours. The land is flat and thinly populated, so large turbines can be spaced out cheaply, and it is close to Karachi, a large market for electricity.
Two developed points: strong/consistent sea winds (esp. April–September); flat open land; low population/cheap land; near Karachi/national grid; few obstacles to wind.
(b) Output varies because wind speed changes, so it cannot provide a steady supply; turbines are expensive to build and the best sites may be far from the grid.
1 mark each for any two: unreliable/variable; high initial cost; noise; visual impact; harm to birds; needs large area; transmission lines needed.
Q15Solar, wind and other renewables · Standard · Paper 2 style · 5 marks
(a)State what is meant by 'bagasse' and explain how it is used to produce electricity.[3]
(b)Suggest why bagasse power can only be produced for part of the year.[2]
Show answer
(a) Bagasse is the dry fibrous waste left after juice is crushed out of sugar cane. Sugar mills burn it in boilers to make steam, which turns turbines to generate electricity for the mill, with surplus sold to the grid.
1 mark definition (sugar-cane waste after crushing); 1 mark burnt to heat water/steam; 1 mark steam turns turbine/generator, surplus to grid.
(b) Sugar cane is crushed only during the harvest/crushing season (roughly November to March), so bagasse is not available all year unless it is stored.
1 mark seasonal harvest/crushing season; 1 mark storage difficult/bulky so supply stops.
Q16Solar, wind and other renewables · Standard · Paper 2 style · 7 marks
(a)State what is meant by tidal power.[1]
(b)Suggest why the creeks of the Indus delta have been considered for tidal power.[2]
(c)Explain two reasons why Pakistan has not yet developed tidal power.[4]
Show answer
(a) Electricity generated using the rise and fall of the sea's tides to drive turbines.
1 mark.
(b) The delta coast has many narrow creeks where tidal water flows in and out strongly; it is close to Karachi and the coastal industries that need electricity.
1 mark each for any two: many creeks/inlets channel tides; reasonable tidal range; near Karachi demand; unused coastal land.
(c) The technology is very expensive and unproven at large scale, so investors prefer cheaper solar, wind and fossil fuels. Barriers and turbines could harm mangrove forests, fish breeding grounds and the livelihoods of fishing communities in the delta.
Two developed points: high cost/lack of technology; low tidal range in places; environmental damage to mangroves/fishing; silt from the Indus; cyclones/storms; other options cheaper.
Q17Solar, wind and other renewables · Challenge · Paper 2 style · 5 marks
A planning document lists new generating capacity planned for one region (illustrative figures, MW):Hydel 300Wind 100Solar 150Bagasse 50Nuclear 400
(a)Calculate the angle needed to draw each source on a pie chart.[3]
(b)Calculate the percentage of this new capacity that comes from solar and wind together.[1]
(c)Which of the sources in the table is not renewable?[1]
Total 1,000 MW share: hydel 300 → 108°; wind 100 → 36°; solar 150 → 54°; bagasse 50 → 18°; nuclear 400 → 144°. Award 3 for all five correct, 2 for three or four, 1 for two.
(b) 25%
(150 + 100) ÷ 1,000 × 100 = 25%.
(c) Nuclear
1 mark.
Q18Solar, wind and other renewables · Challenge · Paper 2 style · 7 marks
(a)State what is meant by geothermal energy.[1]
(b)Suggest why parts of northern Pakistan and western Balochistan have potential for geothermal energy.[2]
(c)Explain two difficulties of developing geothermal power in these areas.[4]
Show answer
(a) Heat from inside the Earth, carried by hot water or steam, used to generate electricity or heat buildings.
1 mark.
(b) These areas lie in active tectonic zones where plates meet, with hot springs (e.g. in Gilgit-Baltistan) and old volcanic areas (e.g. Chagai), showing heat close to the surface.
1 mark tectonic/plate boundary/earthquake zone; 1 mark evidence: hot springs/volcanic features.
(c) The areas are remote and mountainous, so building plants and long transmission lines to the cities is very costly. Detailed surveys and deep drilling are needed and are expensive and risky, and Pakistan lacks experience and funding for this technology.
Two developed points: remoteness/rugged terrain; distance from demand/transmission cost; high exploration/drilling cost; lack of technology/expertise; earthquake risk; security in Balochistan.
Q19Solar, wind and other renewables · Challenge · Paper 2 style · 6 marks
(a)Read the two views:View A: Pakistan should rely mainly on solar and wind power for its future electricity.View B: Pakistan should continue to rely mainly on hydel and thermal power.Which view do you agree with more? Give reasons for your answer, referring to both views.[6]
Show answer
(a) A: abundant sunshine and coastal wind, no fuel import bill, falling costs, quick to install, clean, rooftop solar reduces load on grid. B: solar and wind are intermittent and need storage or back-up; hydel and thermal give steady base-load; existing plants and Thar coal reserves; grid not designed for many variable sources. Supported judgement.
Levels: L1 (1–2) simple statements; L2 (3–4) developed points for one view or simple for both; L3 (5–6) developed points for both views and a reasoned conclusion.
Q20Solar, wind and other renewables · Challenge · Paper 2 style · 6 marks
(a)Evaluate the extent to which renewable energy can solve the energy problems of remote rural areas of Pakistan. Give reasons for your answer.[6]
Show answer
(a) Yes: off-grid solar home systems, micro-hydel on mountain streams in the north, biogas from dung and small wind turbines on the coast can give power without costly grid extension. Limits: high upfront cost for poor families, batteries expensive, small systems cannot run heavy machinery or tube wells easily, need for maintenance skills, seasonal limits (frozen streams, cloudy monsoon days). Judgement on extent.
Levels: L1 (1–2) simple points; L2 (3–4) developed points one side; L3 (5–6) developed points on both sides with judgement. Credit named types matched to areas (micro-hydel in Gilgit-Baltistan/Chitral, solar in Balochistan/Thar).
Q21Energy supply and demand · Core · Paper 2 style · 5 marks
(a)State what is meant by 'load-shedding'.[1]
(b)Explain two effects of load-shedding on industry.[4]
Show answer
(a) Planned cutting of electricity supply to different areas in turn because demand is greater than supply.
1 mark.
(b) Factories have to stop machines during power cuts, so production falls and export orders may be delivered late or lost. Many firms buy generators and diesel, which raises costs and makes their goods less competitive.
Two developed points: lost production/output; late delivery/lost orders; extra cost of generators/fuel; workers idle/laid off; damage to machinery; investors discouraged.
Q22Energy supply and demand · Core · Paper 2 style · 5 marks
(a)Give three reasons why the demand for electricity in Pakistan has increased.[3]
(b)Suggest two ways in which households can reduce their use of electricity.[2]
Show answer
(a) Rapid population growth; urbanisation, with more homes using fans, air conditioners and refrigerators; growth of industry and the extension of electricity to more villages.
1 mark each for any three: population growth; urbanisation; rising living standards/more appliances; industrial growth; rural electrification; tube wells for irrigation; hotter summers increasing air-conditioner use.
(b) Use energy-saving LED bulbs; switch off lights and appliances when not in use (also: efficient inverter air conditioners, solar water heaters).
1 mark each for any two sensible measures.
Q23Energy supply and demand · Standard · Paper 2 style · 6 marks
Illustrative electricity figures for a country:Summer peak demand: 28,000 MWSummer available supply: 24,500 MWWinter peak demand: 16,000 MW
(a)Calculate the shortfall in electricity at the summer peak.[1]
(b)Calculate the shortfall as a percentage of peak demand. Give your answer to one decimal place.[2]
(c)Calculate the difference between summer and winter peak demand.[1]
(d)Suggest two reasons why demand is much higher in summer than in winter.[2]
Show answer
(a) 3,500 MW
28,000 − 24,500 = 3,500 MW.
(b) 12.5%
M1 3,500 ÷ 28,000 × 100; A1 12.5%.
(c) 12,000 MW
28,000 − 16,000 = 12,000 MW.
(d) Very high temperatures mean heavy use of fans, air conditioners and coolers; tube wells pump water for irrigating summer (kharif) crops.
1 mark each for any two: heat/air conditioning/fans; refrigeration; irrigation tube wells for kharif crops; longer working hours in factories (credit), winter heating mostly uses gas.
Q24Energy supply and demand · Standard · Paper 2 style · 7 marks
In one year a country's power stations generated 140 TWh (terawatt-hours) of electricity, but only 115 TWh was billed to customers (illustrative figures).
(a)Calculate the electricity lost in transmission and distribution.[1]
(b)Calculate the losses as a percentage of electricity generated. Give your answer to one decimal place.[2]
(c)Explain two reasons for high transmission and distribution losses in Pakistan.[4]
Show answer
(a) 25 TWh
140 − 115 = 25 TWh.
(b) 17.9%
M1 25 ÷ 140 × 100; A1 17.9%.
(c) Old, overloaded transmission lines and transformers waste electricity as heat, especially over long distances from hydel stations in the north to cities in the south. Electricity theft through illegal connections (kundas) and meter tampering means power is used but never billed.
Two developed points: old/overloaded infrastructure; long distances; theft/illegal connections; meter tampering; poor maintenance; low-voltage lines in rural areas.
Q25Energy supply and demand · Standard · Paper 2 style · 4 marks
(a)Name one place in Pakistan where a nuclear power station is located.[1]
(b)Explain two advantages and one disadvantage of nuclear power for Pakistan.[3]
Show answer
(a) Karachi (K-2 and K-3 at the KANUPP site) or Chashma (Punjab, C-1 to C-4)
1 mark: Karachi/KANUPP site or Chashma.
(b) Advantages: a small amount of fuel produces a large, steady amount of electricity (base load) regardless of weather; it produces almost no carbon dioxide or smoke. Disadvantage: very high construction cost and the risk of accidents and radioactive waste that must be stored safely for a very long time.
1 mark each for two advantages (reliable base load; little fuel needed/less import bill; low emissions) and 1 mark for a disadvantage (cost; radioactive waste; accident risk; need for foreign technology/fuel; needs cooling water).
Q26Energy supply and demand · Challenge · Paper 2 style · 6 marks
(a)Explain what is meant by 'circular debt' in Pakistan's power sector and why it is a problem.[4]
(b)Suggest two ways the government could reduce circular debt.[2]
Show answer
(a) Circular debt is the build-up of unpaid bills along the chain: consumers and distribution companies do not pay in full (because of theft, losses and subsidies), so the power purchaser cannot pay generating companies, which in turn cannot pay fuel suppliers. Generators then cannot buy fuel, so plants stand idle and load-shedding increases, while the government must use public money to clear the debt.
2 marks meaning: unpaid dues passed along the chain (consumers/DISCOs → purchaser → generators/IPPs → fuel suppliers); 2 marks problem: fuel shortages/idle plants → load-shedding; drain on government budget; discourages investment.
(b) Reduce theft and line losses by better metering and enforcement; improve bill collection and set tariffs that cover costs (with targeted subsidies for the poor only).
1 mark each for any two: reduce theft/losses; better recovery of bills; cost-reflective tariffs; renegotiate contracts with IPPs; privatise/improve DISCO management; shift to cheaper local fuels/renewables.
Q27Energy supply and demand · Challenge · Paper 2 style · 6 marks
(a)Evaluate the extent to which Pakistan's energy shortage is caused by a lack of generating capacity rather than by other factors. Give reasons for your answer.[6]
Show answer
(a) Capacity: demand grew faster than new plants for many years; seasonal fall in hydel output in winter. Other factors: installed capacity now often exceeds demand, but plants stand idle because of circular debt and fuel shortages; expensive imported fuels make electricity costly; transmission bottlenecks prevent power reaching consumers; high losses and theft; inefficient old plants. Judgement on extent.
Levels: L1 (1–2) simple points; L2 (3–4) developed points on one side; L3 (5–6) developed points on capacity and other factors with a judgement.
Q28Thermal power · Core · Paper 2 style · 6 marks
(a)Describe how electricity is generated in a thermal power station.[3]
(b)Give two reasons why thermal power stations are often built near large cities such as Karachi or Lahore.[2]
(c)State one environmental problem caused by thermal power stations.[1]
Show answer
(a) A fuel such as oil, gas or coal is burned to heat water in a boiler; the steam produced turns a turbine; the turbine drives a generator that produces electricity.
1 mark each: fuel burned to heat water/make steam; steam turns turbine; turbine drives generator.
(b) They are close to the market, so less electricity is lost in transmission; coastal or city sites have access to imported fuel by port, pipeline or rail.
1 mark each for any two: near demand/market; less transmission loss; access to fuel (port, gas pipeline); cooling water from sea/river; workers available.
(c) Air pollution from burning fossil fuels (smoke, CO₂, SO₂) causing smog, acid rain and climate change.
1 mark: air pollution/greenhouse gases/acid rain/hot water discharge/ash disposal.
Q29Thermal power · Standard · Paper 2 style · 8 marks
Illustrative cost of generating one unit (kWh) of electricity from different sources: furnace oil Rs 38; imported LNG Rs 27; Thar coal Rs 15; local natural gas Rs 12; hydel Rs 5.
(a)Name one thermal power station in Pakistan and the fuel it uses.[2]
(b)Calculate how many times more expensive electricity from furnace oil is than electricity from hydel power.[1]
(c)Calculate how many times more expensive electricity from imported LNG is than from local gas.[1]
(d)Explain two reasons why many thermal power stations in Pakistan are located near Karachi or close to gas fields. You should develop your answer.[4]
Show answer
(a) Guddu power station, which uses natural gas.
1 mark for a station, 1 mark for its fuel: e.g. Guddu – natural gas; Hub – furnace oil; Port Qasim or Sahiwal – imported coal; Thar coal plants – lignite (local coal); Jamshoro – oil/gas/coal; Muzaffargarh – oil/gas.
(b) 7.6 times
38 ÷ 5 = 7.6.
(c) 2.25 times
27 ÷ 12 = 2.25.
(d) Oil, coal and LNG are imported through Karachi's ports, so stations built near the coast avoid the cost of carrying bulky fuel inland; stations such as Guddu are built close to gas fields and pipelines, so fuel can be supplied cheaply and reliably; Karachi itself is the largest market for electricity.
1 mark for each of two reasons + 1 mark each for development (a consequence or 'which leads to'). Reasons: imported fuel arrives at the ports; near gas fields / pipelines in Sindh; large market (Karachi); sea or river water for cooling; flat land available.
Q30Thermal power · Challenge · Paper 2 style · 6 marks
A country generated electricity from the following sources in one year (illustrative figures, TWh):Thermal (oil, gas, LNG, coal) 85Hydel 38Nuclear 12Wind and solar 5Total 140
(a)Calculate the share of thermal power in the total generation. Give your answer as a percentage to the nearest whole number.[1]
(b)Calculate the angle for thermal power if the data were shown on a pie chart. Give your answer to the nearest degree.[1]
(c)Explain two disadvantages for Pakistan of depending so heavily on thermal power.[4]
Show answer
(a) 61%
85 ÷ 140 × 100 = 60.7% ≈ 61%.
(b) 219°
85 ÷ 140 × 360 = 218.6° ≈ 219°.
(c) Much of the fuel (oil, LNG and some coal) is imported, so a large thermal share raises the import bill and the trade deficit and makes electricity prices rise when world fuel prices rise. Burning fossil fuels releases greenhouse gases and pollutants, adding to smog in cities and climate change.
Two developed points: imported fuel → import bill/foreign exchange; price volatility → high tariffs/circular debt; pollution/climate change; non-renewable reserves running out; old inefficient plants waste fuel.
Q31Hydel power · Core · Paper 2 style · 6 marks
(a)Name the river on which each of these dams is built: (i) Tarbela (ii) Mangla.[2]
(b)Explain two reasons why hydel power stations in Pakistan produce less electricity in winter than in summer.[4]
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(a) (i) Indus (ii) Jhelum
1 mark each.
(b) In winter there is little rain and the snow and glaciers in the mountains are frozen, so river flow is low. Water stored in the reservoirs is also released mainly for irrigation needs and levels fall towards the end of winter, so less water flows through the turbines.
Two developed points: low river flow in winter → less water through turbines; snow/ice melt only in summer; monsoon rain in summer; reservoir levels low/drawn down; irrigation release priorities.
Q32Hydel power · Challenge · Paper 2 style · 8 marks
(a)State two advantages of hydel power compared with thermal power.[2]
(b)Read the two views:View A: Pakistan should build more large dams such as Diamer-Bhasha.View B: Pakistan should build small hydel schemes and other renewables instead of large dams.Which view do you agree with more? Give reasons for your answer, referring to both views.[6]
Show answer
(a) It uses a renewable resource with no fuel cost, so electricity is cheap once the dam is built; it causes no air pollution.
1 mark each for any two: renewable; no fuel imports; cheap running costs; no air pollution; dams also store water for irrigation and flood control.
(b) A: large dams give big amounts of cheap electricity and store water for irrigation and flood control, compensate for silting of Tarbela and Mangla. B: large dams are very expensive and take many years, displace people, flood land and heritage sites, silt up, are in earthquake zones and far from demand; small schemes and solar/wind are quicker, cheaper and serve remote communities. Supported judgement.
Levels: L1 (1–2) simple; L2 (3–4) developed points one view; L3 (5–6) developed points both views with a reasoned conclusion.
Similar questions
Questions that test the same subtopic in different years, grouped so you can work on one skill at a time.
References only: find each question in its paper (official link where available, otherwise through your school).
Coal, oil and natural gasBanker4 questions · 4/5 sessions
