Questions

Senior IPS officer Alok Kumar Verma, Delhi Police Commissioner was appointed as new Director of the Central Bureau of Investigation. He will have tenure of two years. He was selected by a three-member committee comprising Prime Minister Narendra Modi, Chief Justice J S Khehar and Congress leader Mallikarjun Kharge. He will take over from interim director Rakesh Asthana, who was handed the reins of the premier investigating agency after former director Anil Sinha retired on December 2, 2016.

Magnetic tape can serve as a Secondary storage unit. It is a medium for magnetic recording, made of a thin, magnetizable coating on a long, narrow strip of plastic film.

A 40% solution of Formaldehyde known as Formalin is used in the preservation of biological specimens because of its hardening action on proteins. 

Author of the book A journey  is Tony Blair

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.