SSC CGL Previous Year Questions: General Science - 18 - SSC CGL MCQ

Graphite is one of the solid lubricants used for reducing the friction.These solid lubricants are used between two sliding surfaces.

Nerve cell is the longest cell in the human body

The acid rain contains acidic components, such as sulfuric and nitric acid. Due to acidity present in the rain it is harmful not only to vegetation but other nonliving structures as well. 

In activated sludge process, wastewater with organic matter is aerated in an aeration basin in which microorganisms metabolize the suspended and soluble organic matter. This is an important stage of the treatment of the sewage water.

Caustic soda or sodium hydroxide is an important chemical compound used in various industrial as well as domestic uses. It is a white deliquescent solid - that is tendency to absorb moisture from the air.

Red light scatters much less than lights of other color due to its greater wavelength.

The deep red colour that is present in tomatoes, pink grapefruit, guava and watermelon is caused by lycopene, a carotenoid.

Anticoagulants are not present in wasp as it is not a blood sucking insect and hence do not need it.

Vegetations like tree and other shrubs and plants are effective in absorbing various pollutant gases like nitrogen dioxide, ozone etc. These also absorb particulate matter through their leaves and needles and thereby help to improve air quality.

When a person cries there is a watery discharge from the nose due to activation of lachrymal fluid through nasal cavity

(c) The functions of root hairs is to absorb water and mineral nutrients present in the soil and take this solution up through the roots to the rest of the plant. Root hair cells do not carry out photosynthesis as they do not contain chloroplasts.

In agriculture, a catch crop is a fast-growing crop that is grown simultaneously with, or between successive plantings of a main crop.

Carotenoids protect the plant from damage from UV light and this protection is attributed to their antioxidant properties: they are able to absorb the harmful oxidative chemicals produced during photosynthesis, the process whereby plants make energy from sunlight.

Ethanol is obtained from the agricultural feedstocks through the process of fermentation. It is a renewable source of energy and blended with petrol in different proportions.

The substance that causes the worst air pollution is carbon monoxide (CO). Carbon monoxide combines with hemoglobin of blood to form carbaminohemoglobin which fails to carry oxygen to body tissues, causing oxygen starvation.

Boiling occurs only when the vapor pressure of the liquid is equal to the surrounding atmospheric pressure.

Covalent compounds have low melting and boiling points and not undergo very fast reactions.

The properties of a mixture are same as that of their components.

Several units of Vinyl Chloride polymerized to form Poly Vinyl Chloride (PVC).

Polarized are used to eliminate the glares produced by different light sources. The polaroid glasses significantly attenuate the source of the glare that is the horizontally polarized light and helps in better visibility and contrast. 

Insulators are substances which do not permit the electricity to pass through it due to very high electrical resistance.

Chromium, nickel are the major components of stainless steel along with iron. 

Uranium obtained from mining contains several isotopes of uranium in different compositions, such as U-234, U-235, and U-238. Through Enrichment of uranium the percentage of fissile uranium (U-235) is increased. 

A refrigerator works on with the help of five basic components: a fluid refrigerant; a compressor, a condenser coil, an evaporator coil and an expansion device. The compressor constricts the refrigerant vapour, raising its pressure, and pushes it into the coils on the outside of the refrigerator. When the hot gas in the coils meets the cooler air temperature of the surroundings, it turns into liquid. In the liquid form at high pressure, the refrigerant cools down as it flows into the coils inside the freezer and the fridge. The refrigerant absorbs the heat inside the fridge, cooling down the air. Lastly, the refrigerant evaporates and then flows back to the compressor, where the cycle repeats itself.

Salivary gland contains an enzyme called ptyalin which breaks down starch into simpler sugars such as maltose and dextrin that can be further broken down in the small intestine.

The femur is the proximal bone of the hindlimb in tetrapod vertebrates. the femur serves an important weight-bearing function and is an essential component of the lower kinetic chain. The robust shape of the femur provides many sturdy attachment points for the powerful muscles of the hip and knee that contribute to walking and other propulsive movements.

The time period of a pendulum is inversely proportional to gravity. The gravity of the Moon is six times less than that of the Earth, hence the time period of a pendulum on the Moon is more than that on the Earth.

The function of ball bearings in a wheel is to convert kinetic friction into rolling friction.

shock absorbers are hydraulic (oil) pump like devices that help to control the impact and rebound movement of your vehicle’s springs and suspension. Along with smoothening out bumps and vibrations, the key role of the shock absorber is to ensure that the vehicle’s tyres remain in contact with the road surface at all times.

Propellant is the chemical mixture burned to produce thrust in rockets and consists of a fuel and an oxidizer. An oxidizer is an agent that releases oxygen for combination with a fuel. In combination with an oxidizer such as liquid oxygen, liquid hydrogen yields the highest specific impulse, or efficiency in relation to the amount of propellant consumed, of any known rocket propellant.