General Science Online Quiz Test

A spherical ball made of steel when dropped in a mercury container will be on the surface of mercury because the density of mercury is higher than that of steel.

Electrostatic precipitator is used to control the pollution of air. It is a filterless device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit.

Bats navigate and find insect prey using echolocation. They produce ultrasound. The sound waves emitted by bats bounce off objects in their environment. Then, the sounds return to the bats' ears, which are finely tuned to recognize their own unique calls.

Cadmium is not a radioactive element. Uranium, Thorium and Radium are radioactive elements.

Soda water is a carbonated drink where CO₂ is dissolved in water to form carbonic acid, hence it is acidic in nature.

The tip of the match-stick is made of an oxidizing agent such as potassium chlorate, mixed with sulphur, fillers and glass powder. The side of the box contains red phosphorus, binder and powdered glass.

The best wavelengths of visible light for photosynthesis fall within the blue range (425–450 nm) and red range (600–700 nm). Therefore, the best light sources for photosynthesis should ideally emit light in the blue and red ranges. Green light is the least effective in photosynthesis.

Zinc is the metal which presents in insulin. Insulin is a hormone that regulates the level of sugar (glucose) in the blood and that is produced by the beta cells of the islets of Langerhans in the pancreas. In humans, insulin is stored as a crystalline hexamer containing two zinc ions and one calcium ion. The chemical formula of insulin is C₂₅₇H₃₈₃N₆₅O₇₇S₆.

Anadromous fish lives mostly in the ocean but during reproduction go to fresh water stream. Hilsa and Salmon are anadromous fish.

Fluoride or fluorine deficiency can lead to tooth decay and possibly osteoporosis. Consuming enough fluoride can make tooth decay less likely and may strengthen bones. Fluoride is a mineral stored in teeth and bones that strengthens them by aiding in the retention of calcium.