Which of the following statements best describes hydrogen as a fuel?
(a) Hydrogen has a lower energy content per unit mass than conventional fossil fuels, making it less efficient for transportation.
(b) The primary challenge in using hydrogen as a fuel is its low energy density by volume, requiring advanced storage and transportation solutions.
(c) Hydrogen fuel can be directly used in internal combustion engines without any modifications, making it a viable alternative to petrol and diesel.
(d) The electrolysis process used to produce hydrogen is always carbon-neutral, regardless of the energy source used.

Question

Which of the following statements best describes hydrogen as a fuel?
(a) Hydrogen has a lower energy content per unit mass than conventional fossil fuels, making it less efficient for transportation.
(b) The primary challenge in using hydrogen as a fuel is its low energy density by volume, requiring advanced storage and transportation solutions.
(c) Hydrogen fuel can be directly used in internal combustion engines without any modifications, making it a viable alternative to petrol and diesel.
(d) The electrolysis process used to produce hydrogen is always carbon-neutral, regardless of the energy source used.

ONLiNE UPSC · Accepted Answer

Correct options (b): Hydrogen has high energy per unit mass but very low energy density per unit volume, meaning it takes up a lot of space unless compressed or liquefied. This makes storage and transportation difficult, requiring high-pressure tanks, cryogenic storage, or advanced materials.

Other incorrect options:

Option (a): Hydrogen actually has a higher energy content per unit mass (about 3 times that of gasoline). However, its low energy density by volume makes storage and transportation challenging. It is not "less efficient" for transportation in terms of energy per mass, but it's storage issues make it less convenient.

Option (c): Hydrogen can be used in modified internal combustion engines (ICEs), but not without modifications. It requires different fuel injection and ignition systems to handle its unique properties. The most efficient way to use hydrogen is in fuel cells, not combustion engines.

Option (d): Electrolysis is only carbon-neutral if powered by renewable energy (like solar or wind).If powered by fossil-fuel-based electricity, it can produce significant carbon emissions. Most hydrogen today is produced from natural gas (gray hydrogen), which emits CO2.

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M Question 1	⏱ 0
Which of the following statements best describes hydrogen as a fuel? (a) Hydrogen has a lower energy content per unit mass than conventional fossil fuels, making it less efficient for transportation. (b) The primary challenge in using hydrogen as a fuel is its low energy density by volume, requiring advanced storage and transportation solutions. (c) Hydrogen fuel can be directly used in internal combustion engines without any modifications, making it a viable alternative to petrol and diesel. (d) The electrolysis process used to produce hydrogen is always carbon-neutral, regardless of the energy source used.