Sources of energy Worksheet-10

Sources of energy Worksheet-10

 

  1. What is greenhouse effect?

 

  1. Name the gaseous fuel, out of the following which has the highest calorific value :

Hydrogen, Methane, LPG, Biogas

 

  1. Why CNG is considered an environmental friendly fuel?

 

  1. Name a fraction obtained during refining of petroleum which is not used as a fuel.

 

  1. Which of the following gases is a major constituent of biogas: Carbon monoxide, hydrogen, methane, carbon dioxide?

 

  1. How is the increase in demand for energy affecting our environment adversely?

 

  1. Which one of the following is a renewable resource :

Natural gas, Petroleum, Ground water, Coal?

 

  1. For producing electricity, the energy from flowing water is preferred to energy obtained by burning coke. State two reasons for it.

 

  1. What is a solar cell? Name two materials mostly used for making solar cells.

 

  1. What type of mixtures are separated by fractional distillation? Name the fraction of crude oil whose boiling point is more than 350°C. Where is it mostly used as a fuel?

 

Answer:

  1. The glass roof and glass walls of a greenhouse allow heat and sunlight to enter it but do not allow heat (infrared radiation) to escape. So greenhouse gets warmed.

 

  1. Hydrogen.

 

  1. CNG does not produce toxic gases on burning.

 

  1. Lubricating oil.

 

  1. Methane (75%).

 

  1. We use fossil fuels to meet the increased energy demands. The pollutants so produced adversely affect the composition of the environment.

 

  1. Ground water.

 

  1. (i) Production of electricity from water is pollution free.

(ii) Water energy is a renewable source of energy. Coke is a non-renewable source of energy and causes pollution on burning.

 

  1. A solar cell is a device which converts solar energy directly into electric energy. Silicon and Germanium are the two most commonly used materials for making solar cells.

 

  1. The various components of a mixture should have different boiling points if these are to be separated by fractional distillation.

Fuel oil is the fraction of crude oil (petroleum) whose boiling point is above 350°C. It is used as a fuel in various industries to heat boilers because it does not leave any residue after burning.