Test : General Science - 4 - Defence MCQ

Electromagnetic waves are propagated by oscillating electric and magnetic fields oscillating at right angles to each other. They are not deflected by electric or magnetic field. They can show interference or diffraction, are transverse waves, may be polarized and need no medium of propagation.

Zacharias Janssen was a Dutch spectacle-maker from Middelburg associated with the invention of the first Optical telescope. He is also credited for inventing the first truly compound microscope.

Super cooling is the process of chilling a liquid below its freezing point, without it becoming solid.

The sextant is an instrument used to measure angles. Mainly used at sea, the tool is so named because its arc is one sixth of a circle – 60 degrees.
 

Bauxite is an ore of Aluminum, which is found in the form of Hydrated Aluminum Oxides.

The common composition of solder is 32% Tin, 68% Lead. This combination has a low melting point and is useful for soldering components that are sensitive to heat.

Soap is a combination of animal fat or plant oil and caustic soda. Many vegetable fats including olive oil, palm kernel oil and coconut oil are also used in soap making.

Amino acids are required for the synthesis of body protein and other important nitrogen-containing compounds. Amino acids are constituents of protein and act as precursors for many co-enzymes, hormones, nucleic acid, etc.

Conditions which increase the rate of evaporation also increase the rate of transpiration. Transpiration is more rapid in hot, dry and windy conditions than it is in still or humid conditions.

The Kyoto Protocol is an international treaty, which extends the 1992 United Nations Framework Convention on Climate Change (UNFCCC) that commits State Parties to reduce greenhouse gases emissions.

It is caused by the excessive use of alcoholic beverage. Liver Cirrhosis is a serious condition where normal liver tissue is replaced by scar tissue.

 Bright’s disease is also known as uremia which affects the kidney. It fuses the physiology of kidney; as result, the amount of urea increases in blood.

Pneumoconiosis is an occupational lung disease and a restrictive lung disease caused by the inhalation of dust, often in mines. The miners feel difficulty in breathing.

Gout is a disease caused by high level of uric acid in the blood (hyperuricemia). It causes an attack of sudden burning pain, stiffness and swelling in a joint.

As per question; Polio, whooping cough and smallpox can control by vaccination but there is no vaccination available for diabetes. Diabetes is a disease related to pancreas which is caused due to insufficient of insulin in the blood.

A rectifier is an electrical device composed of one or more diodes that converts alternating current (AC) to direct current (DC).

The Nobel Prize in Physics 1930 was awarded to Sir Chandrasekhara Venkata Raman "for his work on the scattering of light and for the discovery of the effect named after him.

The Siemens (symbol S) is the derived unit of electric conductance.

The chemical formula of Sodium Benzoate is NaC7H5O2. It is widely used as food preservative.

Humus usually refers to the natural decay of material such as leaves in the soil’s top layer. It is a dark organic material that forms in the soil when plant and animal matter decays.