General Science Online Quiz Test

The energy crisis is a result of many different strains on our natural resources. There is a strain on fossil fuels such as oil, gas, and coal due to overconsumption – which then, in turn, can put a strain on our water and oxygen resources by causing pollution.

Complementary colours are pairs of colours which, when combined or mixed, cancel each other out by producing white or black. Examples of complementary colour combinations are: Red and green; yellow and blue (purple).

A hygrometer is an instrument used in meteorological science to measure the humidity, or amount of water vapour in the air.

Smoke is formed due to solid dispersed in gas. Smoke is a collection of tiny unburnt particles. It is a collection of tiny solid, liquid and gas particles — mostly carbon (soot), tar, oils and ash. Here solid acts as a dispersed phase and gas acts as a dispersed medium.

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.

Mercury vapour and argon is the most commonly used substance in fluorescent tubes. A tube is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. Argon gas is used in fluorescent tubes to stop the oxygen from corroding the hot tungsten filament.

The age of a tree can be determined by counting the rings from the pith of the trunk to the bark. Tree rings are the most accurate indicator of a tree's age. Finding the age of a tree by counting annual growth rings is called dendrochronology.

There are two types of vitamins: water-soluble and fat-soluble. Vitamin C and members of the vitamin B complex are water-soluble. Water-soluble vitamins are easily destroyed or washed out during food storage and preparation.

Leaves are green due to the presence of a green-coloured pigment, called chlorophyll. Chlorophyll is important because it helps plants make energy from sunlight—a process called photosynthesis.

BCG (Bacille Calmette-Guerin) is a vaccine for tuberculosis (also known as TB) disease. TB is a serious infection that affects the lungs and sometimes other parts of the body, such as the brain (meningitis), bones, joints and kidneys.