General Science Mixed Quiz: Set 58

Convection is the transfer of heat by the bodily movement of the particles of a fluid. The part that is heated expands, becomes lighter and rises, and colder, denser fluid sinks to take its place, so a circulating convection current is set up.

Hooke's law holds only as far as the limit of proportionality, and that limit is either equal to or lower than the elastic limit, so statements 1 and 4 are the correct pair.

The fossil of Archaeopteryx carries feathers and wings like a bird together with teeth in the jaws, claws on the wings and a long tail with bones, all reptilian features, so it stands as the standard example of a connecting link in the fossil record.

Pisciculture is the rearing of fish in ponds, tanks and other managed waters, the Latin word piscis meaning fish.

A change of state is governed by the energy of the particles. When a solid absorbs heat its particles vibrate harder until the force holding them in the lattice is overcome and it melts; further heat lets the liquid particles escape as vapour.

Galileo was the first to argue that, with air resistance removed, every body falls with the same acceleration regardless of its mass.

Common salt is sodium chloride, in which sodium and chlorine are chemically combined in a fixed ratio by mass, and the result has properties quite unlike either element, since sodium reacts violently with water and chlorine is a poisonous gas while their compound is eaten daily.

In electroplating the article to be coated is made the cathode, the plating metal serves as the anode, and both are dipped in an electrolyte containing a salt of that metal.

Pinctada margaritifera is the black lip pearl oyster, a bivalve mollusc of the warm shallow water of the Indo-Pacific, where it fastens itself to coral reefs by strong threads.

Litmus is a purple dye taken from lichens, and in the classification used in school science lichens are placed in Thallophyta, the group of simple plants whose body is an undifferentiated thallus with no true root, stem or leaf.

In 1924 Satyendra Nath Bose sent Albert Einstein a paper deriving Planck s radiation law by counting indistinguishable light quanta.

Ultraviolet light is a transverse wave, not a longitudinal one, so this statement is the wrong one. In an electromagnetic wave the electric and magnetic fields vibrate at right angles to each other and to the direction the wave travels, which is the definition of a transverse wave.

The particles of a colloid are between one and one thousand nanometres across, which is large enough to scatter a beam of light sideways and make the path of the beam visible.

In human beings the sperm meets and fuses with the egg inside the fallopian tube, also called the oviduct. The ovary releases one egg in a month, and the funnel shaped mouth of the fallopian tube collects it.

Boyle s law applies to a fixed mass of gas at constant temperature and states that pressure is inversely proportional to volume, so the product of the two is a constant: P1 into V1 equals P2 into V2.

The hepatitis B vaccine was the first vaccine made by recombinant DNA technology.

Milk is an emulsion in which tiny globules of fat are dispersed through water, and those globules fall within the colloidal size range, so milk looks uniform to the eye, does not separate on standing, passes through filter paper and shows the Tyndall effect.

Water contracts as it is cooled from higher temperatures like any other liquid, but only down to 4 degrees Celsius.

Kerosene and water do not mix, so on standing they form two distinct layers with the lighter kerosene above the denser water.

Plasma is a hot, electrically conducting mixture of free electrons and positive ions produced when a gas is heated or strongly ionised.