Recently, the term "pumped-storage hydropower" is actually and appropriately discussed in the context of which one of the following?
- A.Irrigation of terraced crop fields
- B.Lift irrigation of cereal crops
- C.Long duration energy storage
- D.Rainwater harvesting system
Correct answer
Explanation
The correct answer is C, Long duration energy storage. Pumped-storage hydropower stores surplus electricity by pumping water uphill and gives it back when the water flows down through turbines.
A pumped-storage plant has two reservoirs at different heights. When power is cheap or plentiful, for example at midday when solar plants generate the most, reversible pumps lift water to the upper reservoir. When demand peaks in the evening, the water is released to the lower reservoir and the same machines run as turbines to generate electricity. It works like a giant rechargeable battery that can supply power for many hours, which is why it is valued for grids with a large share of solar and wind energy. It is the largest form of grid energy storage in the world.
A is wrong: terraced fields are irrigated by channels and gravity flow, not by storage plants.
B is wrong: lift irrigation pumps water to fields for crops, but it does not store energy.
D is wrong: rainwater harvesting collects rain for use or recharge, not to store power.
Exam tip: pumped storage = pump up when power is surplus, generate when it is scarce; a water battery.
Practice Questions
View allWhich one of the following statements with regard to growth of coral reefs is not correct?
- A.Coral can grow abundantly in freshwater.
- B.It requires warm water between 23 °C-25 °C.
- C.It requires shallow saltwater, not deeper than 50 metres.
- D.It requires plenty of sunlight to aid photosynthesis.
Show answer
Reef-building corals are marine animals and die in fresh water, so this statement is false. Corals are tiny polyps that build skeletons of calcium carbonate and live with algae called zooxanthellae inside their tissues.
Read the full explanation →Which one of the following biosphere reserves is spread over three States in India?
- A.Nilgiri
- B.Achanakmar-Amarkantak
- C.Seshachalam
- D.Agasthyamalai
Show answer
The Nilgiri Biosphere Reserve spreads across Tamil Nadu, Kerala and Karnataka. Set up in 1986, Nilgiri was India's first biosphere reserve, and in 2000 it became the first Indian reserve on UNESCO's World Network of Biosphere Reserves.
Read the full explanation →Which of the following is/are renewable source(s) of energy? 1. Fossil fuel 2. Biofuel 3. Uranium 4. Hydropower Select the correct answer using the code given below.
- A.2 only
- B.3 and 4
- C.1 and 3
- D.2 and 4
Show answer
Biofuel and hydropower are renewable because nature replaces them within a human lifetime, while fossil fuels and uranium are not.
Read the full explanation →Which one of the following is NOT decomposed by bacterial action ?
- A.Vegetable remains
- B.Plastic materials
- C.Animal carcasses
- D.Wastes of flowers
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Ordinary plastics are non-biodegradable, so bacteria and fungi cannot break them down in any useful length of time. Most plastics, such as polyethylene, polypropylene and PVC, are long synthetic polymers made from petroleum.
Read the full explanation →According to the Environmental Protection Agency (EPA), which one of the following is the largest source of sulphur dioxide emissions?
- A.Locomotives using fossil fuels
- B.Ships using fossil fuels
- C.Extraction of metals from ores
- D.Power plants using fossil fuels
Show answer
The EPA names the burning of fossil fuels by power plants and other industrial facilities as the largest source of sulphur dioxide.
Read the full explanation →