Questions

A manometer is used to measure a pressure difference between two points.

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.

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

The Council of States (Rajya Sabha) is composed of not more than 250 members, of whom 12 are nominated by the President. The twelve members are chosen by him from among persons having special knowledge or practical experience in literature, science, art, and social service. The Constitution thus adopts the principle of nomination, for according distinguished Indians a place in the Upper Chamber (Rajya Sabha) of Parliament.

When the piece of iron is lowered into the water, the water level in the bucket increases. And so the pressure at the bottom of bucket also increases. Thus the total thrust at bottom also increases. Therefore the spring balance reading increases. Thus (a) is correct.

Electrons orbit around the nucleus is correct about them.

Rainer Weiss, a professor at the Massachusetts Institute of Technology, and Kip Thorne and Barry Barish, both of the California Institute of Technology, were awarded the Nobel Prize in Physics for the discovery of ripples in space-time known as gravitational waves, which were predicted by Albert Einstein a century ago but had never been directly seen.