General Science Online Quiz Test

Teletext is a standard for displaying text and graphics on the TV screen. Teletext sends data in the broadcast signal, hidden in the invisible vertical blanking interval area at the top and bottom of the screen.

Lambert's law is related to illumination. The law states that Illuminance at a point on a plane is proportional to the cosine of the angle of light incident (the angle between the direction of the incident light and the normal to the plane).

Alnico is a family of iron alloys which in addition to iron are composed primarily of aluminium (Al), nickel (Ni), and cobalt (Co), hence the acronym al-ni-co. They also include copper, and sometimes titanium. Alnico alloys are ferromagnetic, and are used to make permanent magnets.

Rainwater is considered the purest form of water available on the Earth. However, the rainwater we receive on earth is not necessarily pure, as it brings down impurities and particles present in the atmosphere along with it. Distilled water is a type of purified water that has had both contaminants and minerals removed.

Peroxyacetyl nitrate is a secondary pollutant present in photochemical smog. It is thermally unstable and decomposes into peroxyethanoyl radicals and nitrogen dioxide gas. It is a lachrymatory substance, meaning that it irritates the lungs and eyes.

Bleaching powder (CaOCl₂) is extensively used for sterilizing water. The process of chlorination has been used for a long time to purify drinking water. Bleaching powder, in an aqueous solution, produces Cl^– and OCl^– ions. Whereas OCl^– ion acts as a good bleaching agent by killing germs and bacteria.

Non-conventional energy (also known as Renewable energy) sources are sources that are renewed by natural processes on a continual basis. Energy generated by using wind, solar, small hydro, tides, geothermal heat and biomass is known as non-conventional energy. Hydroelectric power is a renewable energy source. It uses the energy of running water, without reducing its quantity, to produce electricity.

The fluid part of blood without corpuscles is called Plasma. Blood plasma is fluid part of blood in which corpuscles (blood cells) are absent, but contains proteins and other constituents of whole blood in suspension. Plasma is the largest part (about 55%) of blood.

Starch, glycogen and cellulose are all polymers of glucose. They differ in the type of glucose present and the bonds which link the glucose monomers together.

Vitamin B₁₂, also known as cobalamin, is an essential vitamin necessary for healthy nerve tissue, brain function, and red blood cell production. Rich sources of vitamin B₁₂ are meat, fish, milk, cheese, eggs, etc.