Which one of the following is the exhaust pipe emission from Fuel Cell Electric Vehicles, powered by hydrogen?
- A.Hydrogen peroxide
- B.Hydronium
- C.Oxygen
- D.Water vapour
Correct answer
Explanation
The correct answer is D, Water vapour. A hydrogen fuel cell joins hydrogen with oxygen from the air to make electricity, and the only product that leaves the exhaust is water.
Inside the fuel cell, hydrogen stored in the tank is split at the anode into protons and electrons. The electrons flow through an outside circuit and run the electric motor, while the protons pass through a membrane to the cathode. There they meet oxygen drawn from the air and the returning electrons, forming water (2H2 + O2 = 2H2O). Because no fuel is burnt, a fuel cell vehicle releases no carbon dioxide, carbon monoxide or soot at the tailpipe, only water vapour and some heat.
A is wrong: hydrogen peroxide is not formed as an exhaust product of the cell reaction.
B is wrong: hydronium ions exist only in solution; they are not released as a tailpipe gas.
C is wrong: oxygen is taken in from the air and used up, not given out.
Exam tip: fuel cell = hydrogen + oxygen gives electricity + water; zero tailpipe carbon.
Practice Questions
View allHindustan Aeronautics Limited handed over the first two indigenously designed and manufactured light combat aircrafts to the Indian Air Force in 2016. What is the name of these new combat aircrafts?
- A.Marut
- B.Garud
- C.Tejas
- D.Pushpak
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Tejas is India's indigenous Light Combat Aircraft, and the first two were handed over to the Indian Air Force on 1 July 2016 to form No. 45 Squadron, the Flying Daggers.
Read the full explanation →Which of the following statements about Bitcoin is/are correct? 1. It is a decentralized virtual currency. 2. It is generated through complex computer software systems. 3. The Reserve Bank of India recognized it as a legal tender in January 2016. Select the correct answer using the code given below.
- A.1 only
- B.1 and 2 only
- C.2 and 3 only
- D.1, 2 and 3
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Bitcoin is a decentralised digital currency created by computer software, but the Reserve Bank of India has never made it legal tender.
Read the full explanation →Which one of the following is India's first indigenously designed and developed long-range subsonic cruise missile which can be deployed from multiple platforms?
- A.Astra
- B.Akash
- C.Nirbhay
- D.Shankhnaad
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Nirbhay is the long-range subsonic cruise missile designed and developed in India by the DRDO. Nirbhay was developed by DRDO's Aeronautical Development Establishment in Bengaluru.
Read the full explanation →"Million Minds Augmenting National Aspirations and Knowledge" (MANAK), a scheme under the flagship programme, Innovation in Science Pursuit for Inspired Research (INSPIRE), caters to :
- A.The college students studying in the undergraduate programme in the age group of 19 - 25 years.
- B.The research scholars in recognized research laboratories of national importance.
- C.The college teachers of the country.
- D.The school children studying in classes 6 - 10 in the age group of 10 - 15 years.
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INSPIRE-MANAK is the school-level part of INSPIRE. INSPIRE is run by the Department of Science and Technology to draw young talent into science.
Read the full explanation →Which one of the following statements is not correct?
- A.BrahMos is a supersonic cruise missile made by India and Russian Federation.
- B.The name BrahMos came from two rivers, Brahmaputra of India and Moskva of Russia.
- C.Indian military scientists were capable of integrating BrahMos cruise missile with Sukhoi-30 MKI fighter.
- D.Defence Research and Development Organization is the manufacturer of Sukhoi-30 MKI fighter.
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The Sukhoi-30 MKI is not made by DRDO; it was designed by Russia's Sukhoi bureau and is built in India under licence by Hindustan Aeronautics Limited (HAL) at Nashik.
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