General Science Questions and Answers

Answer: D

Under Dalton's atomic theory the smallest particle that can exist independently is the atom, which he held to be indivisible.

Avogadro later corrected this: for most elements it is the molecule that exists independently, since oxygen occurs as O₂ and nitrogen as N₂. The distinction between the two answers turns on which theory is being asked about.

Answer: C

A superconductor has zero magnetic permeability as well as zero electrical resistance.

It expels magnetic field entirely from its interior - the Meissner effect - making it a perfect diamagnet. This is what lets a magnet levitate above a cooled superconductor.

Answer: D

There are three teaspoons in a tablespoon.

A tablespoon is 15 ml and a teaspoon 5 ml in metric measure, so the ratio holds in either system.

Answer: B

Rice is not a rabi crop - it is the main kharif crop, sown with the monsoon in June and July.

Wheat, mustard and gram are rabi crops, sown in October and November and harvested in March and April on residual moisture and irrigation.

Answer: D

The study of the universe is cosmology - its origin, structure, evolution and eventual fate.

Cosmography, its close relation, is concerned only with describing and mapping what is there. Cosmetology is the study of beauty treatment.

Answer: B

Bamboo is a grass - a member of the family Poaceae, subfamily Bambusoideae.

It has the hollow jointed stem, the sheathing leaves and the flowering habit of a grass, and it is the fastest growing plant on earth, some species adding almost a metre a day.

Answer: B

The ozone layer, in the stratosphere between about 15 and 35 km, shields the earth from the sun's harmful ultraviolet radiation.

Ozone absorbs almost all UV-C and most UV-B, which would otherwise cause skin cancer, cataracts and damage to crops and plankton. Absorbing that energy is also what warms the stratosphere.

Answer: A

Collagen is the major ingredient of leather. It is the fibrous protein of animal skin, and tanning stabilises it by cross-linking the fibres so they no longer rot or dry hard.

Collagen is also the commonest protein in the body, forming the framework of skin, tendon, bone and cartilage.

Answer: A

Quartz is chemically silicon dioxide, SiO₂.

It is used in clocks because it is piezoelectric: an applied voltage makes the crystal flex, and a correctly cut sliver vibrates at an extremely stable 32,768 Hz. Dividing that frequency by two fifteen times gives a one-second pulse.

Answer: C

Francium is the element listed that is liquid at or near room temperature, melting at about 27°C.

It is intensely radioactive and its longest-lived isotope has a half-life of 22 minutes, so only trace quantities have ever existed at one time. Caesium, at 28.5°C, and gallium, at 29.8°C, behave similarly.