Questions

Hawai

India was re-elected as member of executive board of United Nations Educational, Scientific and Cultural Organization (UNESCO). Executive board is UNESCO's top decision-making body. The election was held at 39th session of General Conference of UNESCO in Paris, France. 

UNESCO is UN association that helps safeguard historical and cultural sites around the world. It is special multi-nation organization, framed in 1945 and situated in France. It promotes literacy and sex education as well as improving gender equality in countries around world. The General Conference determines policies and main lines of work of organisation. Its duty is to set programmes and budget of UNESCO. It also elects members of executive board and appoints, every four years, director-general.

The Doppler effect or Doppler shift is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. 

Dust particles such as coal dust(smoke) are fine particle of a solid (carbon in the case of smoke) dispersed in air. They are colloidal systems and the particles are charged either positive or negative. In an applied electrical field, they are attracted towards the opposite electrodes. Movement of the particles towards the electrodes is known as 'electrophoresis'. Hence electrophoresis is applied to remove smoke within the chimeny itself without allowing it to escape into the air and cause nuisance.