CDS (Combined Defence Services) I - General Knowledge Previous Year Question

Correct Option – (a)

• High-density lipoprotein (HDL) is considered “good cholesterol”.
• Cholesterol is a type of fat found in our blood. More cholesterol in our body means that it can float around in the blood and can clog the blood vessels which can cause cardiac arrest.

The rate of change of momentum of a body is equal to the Force.

Momentum = Mass × velocity
Change of momentum →
d(momentum) = mass × d(velocity)
dt dt
Force = mass × acceleration

• Latent heat of vaporization is the amount of heat required to convert unit mass of liquid state material into solid state material without any change in temperature.
• Water sprinkled on roof-top absorbs heat (energy) and evaporates leaving the roof-top cooler than before.
• Water has high specific heat because it needs to absorb a lot of energy to change its temperature.

Pir Panjal Range in the Himalayas is a part of Lesser Himalayas.

• Laterite soils are rich in oxides of iron and aluminum but deficient in nitrogen and potash.
• As it is poor in nitrogen, it is not fertile and poor for agriculture
• It is majorly found in higher areas of Peninsular Plateau.
• It is found as a result of decomposition due to heavy rainfall and high temperature.

• Mediterranean climate is known for hot, dry summers and mild to cool wet winters.
• During the summer, cold currents keep the climate dry and when the season changes, ocean current shifts too. Hence, during the winter, the water having been warmed up in summer moves in and keep the land warn and often brings rain.
• Hence, the annual range of temperature in the Mediterranean climate is lesser than that of Monsoon Climate.

Bakelite

• Union Carbide operated a pesticide plant in Bhopal. The Bhopal Gas Tragedy is considered as one of the world’s largest industrial disaster.
• The factory used to manufacture three pesticides: carbaryl, aldicarb and a formulation of carbaryl and gamma-hexachlorocyclohexane (g-HCH).
• It is estimated that about 40 tonnes of methyl isocyanate (MIC) gas and other chemicals leaked from the Union Carbide factory.
• In some cases, the impact of poisonous gas has passed on to the second and third generation.
• Union Carbide used trade secrecy as a prerogative to withhold information on the exact composition of the leaked gases.

• Germplasm is a living tissue which is maintained for the purpose of animal and plant breeding.
• Germplasm conservation is the most successful method to conserve the genetic traits of endangered and commercially valuable species.
• Germplasm conservation includes Wild species, breeding lines, commercial varieties, special genetic stocks, etc.
• Germplasm preservation includes In-situ conservation and Ex-situ conservation.

• Dengue is caused by Dengue virus (DENV), a mosquito-borne flavivirus. DENV is a single-stranded RNA positive-strand virus.
• Bone marrow is the manufacturing center of blood cells and Dengue fever induces bone marrow suppression resulting in a deficiency of blood cells which further leads to low platelet count.
• Endothelium cells line the interior surface of blood vessels and lymphatic vessels. These cells when infected with Dengue virus combine with platelets and destroy them.

Power is the amount of energy transferred per unit time.

• Two physical systems are said to be in thermal equilibrium when there is no net flow of thermal energy when they are connected to each other in an isolated system.
• The "zeroth law" states that if two systems are at the same time in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.

• German Silver is an alloy of Copper, Zinc, and Nickel, sometimes containing lead and tin too.
• It does not contain silver but it is named after its “silver-white” look.
• Although its composition varies as per commercial requirement, it is widely used in this proportion - copper (50%), zinc (20%) and nickel (30%).
• German silver is very hard and its resistance to corrosion make is favorable for industrial use

• Satluj is a part of the Indus river system on the western side and Brahmaputra (also known as Yaluzangbu or Tsangpo in China) is on the eastern side.
• In 2002, GoI and China signed an MoU for five years upon provision of Hydrological information on Yaluzangbu / Brahmaputra River during flood season by China to India. MoUs in this connection is being extended from time to time.
• In 2010, GoI and China signed an MoU upon provision of hydrological information of Satluj / Langqen Zangbo River during flood season by China to India. This MoU has also been renewed.
• In 2013, a separate “Memorandum of Understanding on Strengthening Cooperation on Trans-Border Rivers” was also signed, in which inter alia the scope of the provision of hydrological information of three hydrological stations has also been enhanced.

• Stalactites: It is a type of rock formation produced by the precipitation of minerals from water dripping through the cave ceiling. It hangs from the ceiling of a cave.
• Stalagmites: It is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings.

According to NASA, the following are the estimated radii of planets in our solar system:

The order in which planets are away from the sun is - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

• Artificial Insemination is the placing of sperm inside the female’s cervix or uterine to achieve pregnancy.
• It is recommended to a couple having trouble in conceiving.
• Intracervical Insemination involves placing raw semen into the vagina by needleless syringe.
• Intrauterine Insemination involves injecting washed sperm into the uterus with a catheter.
• Intrauterine tuboperitoneal insemination involves injecting washed sperm into both the uterus and fallopian tubes.

• When the DNA of a plant had been modified using genetic engineering methods, it is called Genetically modified crops.
• It is widely used to make crops resistant to certain pests and disease.
• It is also used to improve nutrition value in a crop.
• Insect-resistant crops contain genes from the soil bacterium Bacillus thuringiensis.
• GM crops are sometimes discouraged to consume due to the following potential threats: an allergic reaction (allergenicity), gene transfer and outcrossing.

• At 20°C, the speed of sound in air is about 343 meters per second.
• The speed of sound depends on medium, temperature, and pressure of the medium.
• The speed of sound decreases when it passes from solid to the gaseous state of the medium.
• The speed of sound in aluminum is 6420 m/s, in seawater is 1531 m/s and in Hydrogen gas is 1284 m/s.

• The sound of frequencies higher than 20 kHz is known as ultrasonic sound or ultrasound.
• The audible range of sound for human beings varies between 20 Hz to 20000 Hz.
• Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging or sonography is often used in medicine.
• Ultrasonic waves are generated by a transducer that includes a piezoelectric crystal that converts electrical energy (electric current) to mechanical energy (sound waves).

• Pernicious Anemia is a decrease in red blood cells that occurs when the intestines cannot properly absorb vitamin B1.
• Vitamin B₁₂ is also referred to as cobalamin because it contains a metal ion.
• Cyanocobalamin is used in vitamin supplements and pharmaceuticals.
• Symptoms of Vitamin B₁₂ deficiency is the smoothness of the tongue, gastrointestinal disturbances, nervous symptoms.

• The minerals containing iron is known as ferrous and without iron is known as non-ferrous.
• Most of the coals are found in the East Coast of India- Chhattisgarh, Jharkhand, Odisha, etc and most of the ferrous materials are found in Chhattisgarh, Odisha, and Karnataka.
• A landmass surrounded by water from three sides is called Peninsula.
• Gondwana was an ancient supercontinent that contained Africa, South America, Australia, Antarctica, the Indian subcontinent and the Arabian Peninsula.
• The supercontinent began to split due to fissure being created by the Magma below the Earth’s crust.
• Gondwana began to break up and took million years to form the current continent/countries we know.

• This national park is near Wandoor on the Andaman Islands. Hence, it is also known as Wandoor National Park.
• It was established in 1983 under the Wildlife Protection Act of 1972 to protect marine life.
• There are 2 major island groups in the park which are the Twin Islands and the Labyrinth Islands. The type and composition of vegetation vary from island to island.

• Perihelion: The point at which an orbiting planet is closest to the sun.
• Aphelion: The point at which an orbiting planet is farthest from the sun.
• The earth is farthest from the sun about two weeks after Summer Solstice.
• Summer Solstice: It is when one of the Earth’s poles has its maximum tilt towards the Sun. Hence, the earth is farthest away from the Sun at Aphelion, which generally occurs on July 4.
• The Earth is closest to the Sun about two weeks after the winter solstice.
• Winter Solstice: When one of the Earth's poles has its maximum tilt away from the Sun. It usually occurs on 21 or 22 December.

• Reunion Island is in the Indian Ocean but is a region of France.
• This island is above a hotspot in the Earth’s crust.
• The Piton de la Fournaise is a shield volcano in Reunion Island is sometimes called a sister to Hawaiian volcanoes.
• The Andaman and Nicobar Islands is one of the seven Union Territories of India and it has approximately 572 islands. Its capital is Port Blair.
• Lakshadweep Islands is one of the seven Union Territories of India. Its capital is Kavaratti.
• The Maldives situated in the Indian Ocean famous for its beaches, blue lagoons, and extensive coral reefs. Its capital is Male.