SSC CGL Previous Year Questions: General Science - 19 - SSC CGL MCQ

The most common use for asbestos is as a cement additive. By adding asbestos to a mixture of cement, the tensile strength of a sheet of cement would be increased 10 fold. Workers working in the cement industry are exposed to asbestos, getting infected with white lung disease.

Gypsum is a naturally occurring mineral mined from deposits formed by ancient seabeds as a raw material. Composed of calcium sulfate and water, it is used for a variety of manufacturing, industrial, and agricultural uses. Portland cement produced by heating limestone and clay minerals in a kiln to form clinker, grinding the clinker, and adding 2 to 3 percent of gypsum. The addition of gypsum to Portland cement helps in preventing rapid setting of cement.

Iodoform is the organoiodine compound with the formula CHI3. A chemical reaction in which a methyl ketone is oxidized to a carboxylate by reaction with aqueous HO– and I2. The reaction also produces iodoform (CHI3). Iodoform is used as an antiseptic

An artificial ecosystem is represented by aquarium. An aquarium is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed.

Lead in automobile exhaust is carcinogenic to humans causing lung cancer.

The optimum dissolved oxygen level (in mg/litre) required for survival of aquatic organisms is 4-6.

Keibul Lamjao National Park in the Bishnupur district of Manipur is the only floating park in the world.

Edward Jenner is well known around the world for his innovative contribution to immunization and the ultimate eradication of “Small Pox” (1796). Jenner is often called “the father of immunology”, and his work is said to have “saved more lives than the work of any other human”.

seed is associated with Cotton. BT is a family of proteins originating from strains of the bacterium Bacillus thuringiensis. There are more than 200 different types of BT toxins, each affecting different types of insects.

Monazite is a primary ore of several rare earth metals most notably thorium, cerium and lanthanum. Thorium is a highly radioactive metal and could be used as a replacement for uranium in nuclear power generation. Monazite sand deposits are inevitably of the monazite- (Ce) composition.

In coriander, the useful parts are leaves and dried fruits. Coriander is an annual herb in the family Apiaceae. It is also known as Chinese parsley, and in North America the stems and leaves are usually called cilantro.

Amla is called Herbal Indian Doctor because it is used to cure many ailments naturally.

Blood is normally slightly basic, with a normal pH range of 7.35 to 7.45. Usually the body maintains the pH of blood close to 7.40.

Endocrine glands are tissues or organs that excrete chemical substances (hormones) directly into the blood. Common endocrine glands are the hypothalamus, pineal, and adrenal glands. The thyroid gland is found in your throat, just below the jaw. This gland secretes a number of hormones that act on your metabolism. It is the largest endocrine gland in the body.

Whale is the largest mammal.

The second incisors of the elephant are modified into the huge tusks of an elephant. Tusks are used for defense, offense, digging, lifting objects, gathering food, and stripping bark to eat from trees. They also protect the sensitive trunk, which is tucked between them when the elephant charges

An optical fiber is a thin fiber of glass or plastic that can carry light from one end to the other. The study of optical fibers is called fiber optics. Optical fibers are based on the phenomenon of total internal reflection. 

The yellow lamps as street lights use low-pressure sodium-vapour lamps which emits monochromatic yellow light. The sodium-vapour lamp is a gas discharge lamp that uses sodium in an excited state to produce light at a particular wavelength.

Mirage formation is a result of the refraction and the total internal reflection of light in the air. Mirages happen when the ground is very hot and the air is cool. The hot ground warms a layer of air just above the ground. A layer of very warm air near the ground refracts the light from the sky nearly into a U-shaped bend. Our brain thinks the light has travelled in a straight line.

Due to scattering of light the sky appears blue. The Blue light due to its shorter wavelength is scattered more than other colors and hence sky appears blue.

Flint glass is generally used for making lenses and prisms. It is highly refractive lead-containing glass and absorbs most ultraviolet light but comparatively little visible light.

Vulcanization is a chemical process for converting natural rubber or related polymers into more durable materials by the addition of sulfur.

The addition of borax to the pyrex glass resulting in providing extra strength. It provides the glass extra resistance to prevent breakage under heating or cooling.

Radon emits radiation which kills cancerous cells. Although radon is not as widely used for the treatment of cancer now a days.

A concave lens is also known as a “biconcave lens” because of two spherical surfaces bulging inwards. A Concave lens always forms an image which is virtual and erect. Concave lenses are used as a correction for myopia or short nearsightedness because it converges the light rays passing through it. It is also used in binoculars and some telescopes.

Vitamin B-12, also called cobalamin, is a water-soluble vitamin that has a key role in the normal functioning of the brain and nervous system, and the formation of red blood cells.

Chloropicrin is a chemical compound currently used as a broad-spectrum antimicrobial, fungicide, herbicide, insecticide, and nematicide. Chloropicrin is harmful to humans. It can be absorbed systemically through inhalation, ingestion, and the skin. At high concentrations it is severely irritating to the lungs, eyes, and skin.

Modulus of rigidity is defined as the ratio of shear stress to the shear strain: where shear stress is the force which acts is the area on which the force acts is shear strain. The SI unit of Modulus of Rigidity is pascal (pa).

Air at atmospheric pressure is a nearly ideal gas, and sound transmission in air is close to adiabatic for normal frequencies and transmission distances. The total internal energy of the gas through which sound travels remains same.

Caesium is a chemical element. It is a soft, silverygolden alkali metal with a melting point of 28.5 °C (83.3 °F), which makes it one of only five elemental metals that are liquid at or near room temperature. It is used as a getter, a material that combines with and removes trace gases from vacuum tubes. It is also used in atomic clocks, in photoelectric cells and as a catalyst in the hydrogenation of certain organic compounds.