UPSC Prelims 2015 Question:

With reference to 'fuel cells' in which hydrogen-rich fuel and oxygen are used to generate electricity, consider the following statements:

1. If pure hydrogen is used as a fuel, the fuel cell emits heat and water as by-products. 
2. Fuel cells can be used for powering buildings and not for small devices like laptop computers. 3. Fuel cells produce electricity in the form of Alternating Current (AC).
   
   

Which of the statements given above is/are correct?

Explanation: 

• A Fuel Cell uses the chemical energy of hydrogen or other fuels to cleanly and efficiently produce electricity. If hydrogen is the fuel, the only products are electricity, water, and heat. So, statement 1 is correct.
  
  
• Actually a single fuel produces just a tiny amount of electricity. Hence, usually multiple fuel cells are used for electricity production. Thus, fuel cells are unique in terms of the variety of their potential applications; they can use a wide range of fuels and feedstocks and can provide power for systems as large as a utility power station and as small as a laptop computer. So, statement 2 is not correct.
  
  
• Fuel cells produce Direct Current. So, statement 3 is not correct.
  
  

Therefore, option (1) is the correct answer.

Subject: Science & Technology | Recent Developments