General Science Mixed Quiz: Set 186

The field at the centre of a coil is proportional to the number of turns and inversely proportional to the radius, so doubling N and halving R makes it four times larger.

An injury here is fatal because these actions cannot be done at will.

In his 1913 model of the atom, Bohr proposed that electrons move in certain fixed orbits, called stationary states, in which they do not radiate energy.

The correct answer is B, Wilhelm Johannsen, the Danish botanist who gave the words gene, genotype and phenotype, distinguishing the hereditary constitution of an organism from its visible expression.

Sclerenchyma cells are dead at maturity, with thick walls hardened by lignin. Sclerenchyma is the tissue that makes plants hard and stiff.

In a capillary tube the height of rise is directly proportional to the surface tension of the liquid and inversely proportional to its density and the radius of the tube.

A compound microscope uses two converging lenses, the objective and the eyepiece, to give a greatly magnified image of a tiny object.

The Higgs boson found at CERN in 2012 has a mass of about 125 GeV, which among the given options is closest to 100 GeV.

Cinnabar is mercury sulphide, HgS, the chief ore from which mercury is obtained. Cinnabar is a bright red mineral.

A diode does not obey Ohm's law: the current through it is not proportional to the voltage across it. An ohmic conductor gives a straight-line graph of current against voltage, so its resistance stays constant at a fixed temperature.

RNA is usually single-stranded and its sugar, ribose, carries an extra hydroxyl group, which makes the molecule more reactive and easier to break or alter than double-stranded DNA.

German silver is an alloy of copper, zinc and nickel, and its name comes from its white silvery appearance, not from its composition, since it contains no silver at all; it is used for tableware, ornaments and electrical contacts.

Colostrum is the thick, yellowish first milk a mother produces in the first few days after childbirth.

Carbon dioxide is about one and a half times as dense as air, so when released it forms a blanket over the burning material and separates it from atmospheric oxygen, removing one side of the fire triangle.

Antibodies are made by B-lymphocytes, a kind of white blood cell, after they meet a foreign antigen. When a germ or other foreign substance enters the body, B-lymphocytes that recognise its antigen multiply and turn into plasma cells.

Wool is an animal fibre made mainly of the protein keratin. Polymers are giant molecules built from many small repeating units called monomers.

Thyroxine is an animal hormone, made by the thyroid gland in the neck, and it controls the rate of metabolism in the human body.

A black hole forms when a very massive star collapses under its own gravity, and its pull becomes so strong that not even light can escape.

Anthropology, from the Greek 'anthropos' (human) and 'logos' (study), is the science of human beings: how societies and cultures began, how they changed and how people live today.

When an electric current is passed through brine, a concentrated aqueous solution of sodium chloride, the salt decomposes. Chlorine gas is given off at the anode and hydrogen gas at the cathode, while sodium hydroxide is left in the solution near the cathode.