Hippocrates is considered the father of Medical Science. He separated medicine in ancient Greece from superstition and religious beliefs and provided a scientific and practical basis. It was Hippocrates who prepared a code of ethical conduct for doctors, which is still taken by new doctors in the form of 'Hippocratic Oath'. The father of Botany given in the options is Theophrastus, the father of modern chemistry is Robert Boyle and the father of biology and zoology is Aristotle.

Apiculture is the scientific method of beekeeping for honey and wax production. Sericulture is the commercial production of silkworms (silkworms reared on mulberry leaves). Pisciculture is related to fish farming and production on commercial scale in artificial ponds and reservoirs. Viticulture is the branch related to the cultivation and production of grapes from the scientific point of view. Apart from this, floriculture is related to the cultivation of flowers, oliviculture is related to the cultivation of olives and horticulture is related to fruit-vegetable and commercial horticulture.

Soilless agriculture or the scientific method of growing plants in a solution of only water and essential mineral nutrients without soil is called Hydroponics. This technology is a boon for areas where fertile soil is not available or there is scarcity of land. In this, the roots of the plants are kept immersed in nutrient solution and controlled supply of light and oxygen is provided. In option A, hydrostatics is related to the study of hydrostatics, in option B, cybernetics is the study of control and communication between humans and machines, and tillandsias is related to plants growing on atmospheric moisture.

Statements A, C and D are completely true. Pedology is the branch of science that studies the formation, structure and classification of soil. Under tribology, the scientific study of friction, wear and lubricants between surfaces in contact with each other is done. Ethnobotany is a branch of botanical science that studies the traditional use of medicinal and practical plants by local tribals and human communities. Statement B is false because pomology is the study of 'fruits', whereas the study of pollen is called 'palynology'.

The special branch of Botany related to the study of fungi is called Mycology. Antoni Micheli is considered the father of mycology. In option A, Phycology deals with the study of algae. In option C, osteology deals with the study of bones and skeletal system. In option D, Hematology is the branch related to the study of blood and blood related diseases.

Studying the biological systems, behavior of organisms and biological methods found in nature and using that knowledge in the construction of artificial technical systems and engineering equipment is called Bionics. For example, the development of radar based on the sonar system of bats or the design of aircraft based on the flight system of birds. In option B, bionomics deals with the relationship of organisms with the environment and the nervous system of animals. In option C, biometrics is related to the use of mathematical and statistical methods in biology.

Anatomy is the scientific study of the body of living beings and the structure of their internal organs through dissection. In option C, chronology is the study of chronology or periods of time. In option D, odontology is the study of structure, development and diseases of teeth. Hepatology is the medical branch of study of liver and its related disorders.

The study of behavior, physical properties and phenomena of substances at very low temperatures (usually 0°C to -150°C or less) is called Cryogenics. Liquid hydrogen (fuel) and liquid oxygen (oxidizer) are used in cryogenic engines in space launch vehicles. In option B, Selenology is the study of the shape and movement of the Moon. In option C, toxicology is the study of poisons and their side effects. In option D, Horology is the science of measuring time.

The scientific study of birds is called Ornithology. Famous Indian scientist Dr. Salim Ali is called 'Birdman of India'. In option A, Limnology is the study of organisms in fresh water lakes, ponds and ponds. In option B, herpetology is the study of amphibians and reptiles. In option C, Malacology is the study of soft-bodied organisms of the phylum Mollusca.

In astronomy, 'White Dwarf' is an extremely dense, small-sized star which is made up of 'electron degenerate matter' in the last stage of its life cycle. When a medium-mass star (like our Sun) runs out of nuclear fuel, it turns into a white dwarf after becoming a red giant. Astronomy is the main branch of science that studies the objects, stars, planets and galaxies of the universe.

Odometer is a scientific instrument which works on the basis of rotation of the wheel to measure the total distance traveled by a vehicle (car, motorcycle, bicycle etc.). In option A the speedometer tells the instantaneous speed of the vehicle. In option C the anemometer measures the velocity and direction of the wind. In option D, dynamometer is an instrument that measures the mechanical power generated by the engine.

Aerometer instrument is used to measure the density and weight of air and other gases. Ammeter measures the electric current flowing in an electric circuit in amperes. Anemometer is an instrument that measures the direction, force and speed of wind. Altimeter is used to measure the height of flying planes and high places above sea level.

Earthquake waves (P, S and L waves) are recorded by an instrument called seismograph and its intensity is measured on the mathematical Richter scale in the value of 0 to 9. This scale was invented by Charles Francis Richer in 1935. Each next digit on the Richter scale represents 10 times more amplitude and about 32 times more energy than the previous digit. During an earthquake, primary (P) waves arrive first and surface (L) waves arrive last and cause the most destruction.

Statements A, C and D are correct. An endoscope is an instrument with a light tube through which the internal organs of the body (such as stomach, intestine) are examined. Stethoscope works on the principle of multiple reflection of sound which allows the doctor to hear the heartbeats of the heart and lungs. Arterial blood pressure is measured with a sphygmomanometer. Statement B is incorrect because ECG (Electrocardiograph) is used to diagnose heart diseases, whereas EEG (Electroencephalograph) is used to measure brain activity.

The moisture or relative humidity present in the atmosphere is measured by a hygrometer (also called psychrometer). Relative density of different liquids is determined by hydrometer. Lactometer is based on Archimedes' law of buoyancy which measures the concentration/purity and relative density of milk. The pressure of gases in closed tubes or vessels is measured by manometer.

All four statements are completely true. Barometer is the main instrument for measuring atmospheric pressure. Air flow is always from high air pressure to low air pressure. When suddenly low air pressure is formed at some place, the mercury of the barometer suddenly falls and winds come from all sides at high speed, causing storms. Due to gradual falling of mercury, moist winds come and cause rain and as the mercury rises, high air pressure is created which keeps the day clear.

The instrument that measures the intensity of the sun's rays and the amount of solar radiation is called Actiometer. In option A, Crescograph is an instrument that measures the rate of growth of plants at a very fine level, which was discovered by the great Indian scientist Sir Jagadish Chandra Bose. Pyrometers are used to measure high temperatures (like the heat of the sun and furnaces).

The standard unit of measuring the depth of the sea is fathom and the value of 1 fathom is equal to 6 feet (about 1.828 meters). On this basis, the fathometer measures the depth by the reflection time of sound waves. The distance covered by ships in the sea is measured in nautical miles (1 nautical mile = 1.852 kilometers). The unit of speed of ships is called 'Knot'.

Nephroscope is a scientific instrument which is used to observe the direction, speed and speed of clouds floating in the sky. In option A, rain gauge is an instrument that measures the amount of rainfall. Bolometer in option C is a sensitive instrument measuring electromagnetic radiation energy of any frequency. In option D, altimeter is an instrument for measuring altitude.

Microscope is an optical instrument with the help of which microscopic organisms, cells and microscopic particles which are not visible to the naked eye can be seen in magnified form. In option A, periscope is used in submarines to view objects above the water surface. In option B, hydroscope is an instrument for observing underwater and electroscope detects the presence of electric charge on an object.

The International System of Units (SI) was implemented unanimously in the year 1971 at the International Conference of Weights and Measures. This is a modified and enlarged form of the MKS method. It has 7 basic quantities: length (meter), mass (kilogram), time (second), temperature (kelvin), electric current (ampere), luminous intensity (candela), and amount of substance (mol). Apart from this, plane angle (radian) and cubic angle (steradian) are also two complementary units.

Momentum (p = m × v) is a vector quantity. Its SI unit is kilogram-meter/second (kg·m/s). Since force = rate of change of momentum (F = dp/dt), momentum is also written in terms of 'Newton-second' (N·s). Option A shows the units of CGS system. The dimension of momentum is MLT⁻¹.

Acceleration (Acceleration = change in velocity / time taken) is a vector quantity. Its SI unit is meter per second² (m/s²). If the velocity increases with time then acceleration is positive, and if the velocity decreases then it is called negative acceleration or 'retardation'. In option A, m/s is the unit of speed and velocity.

Wavelength is a type of length or distance, hence its SI unit is 'meter' (m). Although the wavelengths of light and microwaves are expressed in very small units such as angstrom (1 Å = 10⁻¹⁰ m) or nanometers, the basic SI unit is the meter. In option A, Hertz is the unit of frequency. In option C, m/s is the unit of wave velocity.

Relative density is the ratio of the density of a substance to the density of pure water at 4°C. Since it is the ratio of two similar physical quantities (density/density), it is a dimensionless and unitless quantity. Options A and B are units of density in CGS and SI systems respectively.

The unit for measuring the loudness of sound is 'bel', and its tenth part 'decibel' (dB) is used as a practical unit. The loudness of normal conversation is 30 to 60 dB. According to the World Health Organization (WHO), sounds up to 45 dB are audible and sounds above 85 dB can cause deafness if heard continuously. 120 dB is the limit of unbearable sound.

In food and nutrition science, the chemical energy obtained from foods is measured in 'calories' (or kilocalories). 1 calorie is the amount of energy required to raise the temperature of 1 gram of water by 1°C. 1 calorie = 4.184 joules. Options A, B and D are scales for measuring temperature.

The formula for both pressure (Pressure = force / area) and stress (Stress = internal resistive force / area) is force per unit area. Therefore, the SI unit of both of them is Newton/meter² (N/m²) or Pascal (Pa) and their dimensions [M L⁻¹ T⁻²] are the same. In option A the unit of power is watt. In option B the unit of force is Newton.

Light year is a unit of measuring extremely large astronomical distances. The distance covered by light in vacuum in 1 Julian year (365.25 days) is called 1 light year. 1 light year = 9.46 × 10¹⁵ meters (or 9.46 × 10¹² km). The largest unit of distance measurement is 'parsec', and 1 parsec = 3.26 light years = 3.08 × 10¹⁶ meters.

SI prefixes are used when the quantity being measured is very large or very small compared to the base unit. Hecto = 10², Kilo = 10³, Mega = 10⁶, Giga = 10⁹, Terra = 10¹², Peta = 10¹⁵, Exa = 10¹8. Similarly, in negative powers: centi = 10⁻², milli = 10⁻³, micro = 10⁻⁶, nano = 10⁻⁹, pico = 10⁻¹², femto = 10⁻¹⁵.

The traditional unit of measuring the rate of nuclear disintegration of radioactive substances is 'Curie'. The amount of radioactive material in which 3.7 × 10¹⁰ nuclear disintegrations occur per second is called 1 Curie. It was named in honor of Madame Marie Curie. The unit of radioactivity in the SI system is 'Becquerel (Bq)' (1 Bq = 1 disintegration per second).

Kilowatt hour (kWh) is the standard unit of commercial electrical energy measurement, which is commonly called '1 unit of electricity'. An appliance of 1000 watt capacity consumes 1 kWh of energy when it runs for 1 hour. 1 kWh = 1000 watts × 3600 seconds = 36,00,000 joules = 3.6 × 10⁶ joules = 3.6 megajoules (MJ).

All four statements are completely true. The conversion formula of temperature scales is (C-0)/100 = (F-32)/180 = (K-273)/100. Putting C = -40 in this formula gives F = -40, hence at -40° both the scales give the same reading. The melting point of water is 0°C = 32°F = 273.15 K and the boiling point is 100°C = 212°F = 373.15 K. The value of 0°C is 32°F in Fahrenheit and the value of 10°C is (10 × 1.8 + 32) = 50°F.

The behavior of water is abnormal between 0°C to 4°C (Anomalous expansion of water). When 0°C water is heated, up to 4°C its volume decreases and density increases. At 4°C the relative density of water is maximum (1000 kg/m³) and volume is minimum. On heating above 4°C the volume again increases and the density decreases. Due to this unusual expansion, underwater life survives even when the upper surface of lakes and ponds freezes in winter.

Electric current is a scalar quantity because it does not follow the vector addition laws. Physical quantities which have only magnitude are called scalar quantities (e.g. distance, speed, mass, volume, temperature, pressure, work, energy, electric current). Options A, B and C are vector quantities because they have definite direction along with magnitude and follow vector algebra.

Therm (therm, symbol: thm) is a traditional non-SI unit of thermal energy, used primarily in natural gas supply and commercial fuel measurement. 1 dram is equivalent to 100,000 British thermal units (BTU), which is approximately 105.5 megajoules (MJ) or 25,200 kilocalories.

The SI unit of electric potential difference is 'Volt'. The unit of inductance is 'Henry'. The unit of specific resistance (resistivity) of a conductor is 'ohm-meter' (Ω·m). The unit of resistance to flow of liquids i.e. viscosity is 'Poise' or Pascal-second. The unit of wavelength of light is angstrom, candela of illumination intensity and farad of electric capacitance.

Central Drug Research Institute (CDRI) is located in Lucknow (Uttar Pradesh). This is the first major drug research institute of the country, which was established after independence on February 17, 1951. It is an apex laboratory working under the Council of Scientific and Industrial Research (CSIR) which is engaged in new drug development and health research.

Central Sheep Breeding Farm is situated in Hisar (Haryana). Central Veterinary Research Institute (IVRI) is located at Izzat Nagar, Bareilly (Uttar Pradesh). Central Food Technological Research Institute (CFTRI) is located in Mysore (Karnataka). National Dairy Research Institute (NDRI) is located in Karnal (Haryana).

In 1947, John Bardeen and Walter Barten, under the leadership of William Shockley at Bell Laboratories (USA), invented the world's first successful point-contact transistor. This revolutionary invention replaced vacuum tubes in the field of electronics and laid the foundation for the modern computer and semiconductor revolution. For this achievement, these three scientists were given the Nobel Prize for Physics in 1956.

All four statements are completely true. In the year 1928, Sir Alexander Fleming discovered the first antibiotic called penicillin in the laboratory from a fungus called Penicillium notatum. This discovery revolutionized the medical field and saved millions of lives. For this, Alexander Fleming, Howard Florey and Ernst Chain were jointly awarded the Nobel Prize in Medicine in 1945.

Indian botanist Prof. Satish Chandra Maheshwari and S. Guha Mukherjee, while doing historical research in the field of Plant Tissue Culture, developed Haploid Plants for the first time in the world by culturing the pollen grains of Datura innoxia. This technology paved a new path for improvement in plant breeding and genetics.

The ancient Greek philosopher Aristotle is considered the 'Father of Biology' and 'Father of Zoology'. He presented scientific classification of organisms for the first time and studied their physical structure and life cycle. Theophrastus given in the options is considered the 'Father of Botany' and Lamarck gave the word 'Biology'.

The ball point pen was invented in the year 1931 by the Hungarian journalist Ladislao Jose Biro (Lazio Joseph Biro) together with his brother. He used a quick-drying ink and a small metal ball rotating on the nib that wrote smoothly without spreading on the paper. In his honor, ball pen is also called 'Biro' in many countries.

Dr. Salim Ali (12 November 1896 – 20 June 1987) was a famous ornithologist and naturalist of India. He is called the 'Birdman' of India. He conducted the first systematic survey of birds across India and wrote several books (such as 'The Books of Indian Birds'). He had an important role in making Keoladeo National Park in Bharatpur a bird sanctuary and saving the Silent Valley Park in Kerala. SAC ON was established in Coimbatore in his honor in 1990.

Indian-origin American physicist Dr. Narinder Singh Kapani is considered the 'Father of Fiber Optics'. Through his experiments during 1952-1956, he proved that light rays can be sent to long distances through fine tubes of ultra-pure silica/glass without degradation by the principle of total internal reflection. Today, optical fiber is the backbone of high-speed Internet and telecommunication.

X-rays were discovered on 8 November 1895 by German physicist Wilhelm Conrad Roentgen. These are high energy electromagnetic waves with wavelengths of 0.01 to 10 nanometers, which can pass through the soft tissues of the human body and take pictures (X-ray images) of the bones. For this epoch-making discovery, Roentgen was awarded the first Nobel Prize for Physics in 1901.

The full name of RADAR is 'Radio Detection and Ranging'. It detects the direction, distance and speed of distant objects (aircraft, ship, etc.) using radio/microwaves. In 1935 the Scottish physicist Sir Robert Watson Watt demonstrated and patented the first practical radar system, which brought great success to Britain in air defense in World War II.

Isaac Newton propounded the universal law of gravitation and three laws of motion. Albert Einstein propounded the theory of relativity (E = mc²). Alfred Nobel invented dynamite (explosive) in 1867. Galileo Galilei was the first to study celestial bodies (Moon, satellites of Jupiter) by refining the telescope. (Radio was invented by Marconi).

Theodore Maiman constructed the world's first successful laser using a ruby ​​crystal at Hughes Research Laboratories on 16 May 1960. The full form of laser is 'Light Amplification by Stimulated Emission of Radiation'. It produces monochromatic, highly coherent and intense light beam, which is used in medicine (surgery), communication, holography, distance measurement and industries.

The Wright brothers, Orville Wright and Wilbur Wright, residents of Ohio, USA, are credited with the invention of the airplane. He successfully completed the first controlled, sustained manned flight in his self-built motorized aircraft 'Wright Flyer' on 17 December 1903 at Kitty Hawk, North Carolina.

Alexander Graham Bell is known as the inventor of the telephone. He received the first US patent for the telephone on March 7, 1876, and sent the first historic voice message to his assistant Thomas Watson on March 10, 1876: "Mr. Watson, come here, I want to see you." In option C, Baird invented television and Marconi invented wireless telegraphy/radio.

Dr. Homi Jahangir Bhabha (30 October 1909 – 24 January 1966) was an eminent nuclear physicist of India, born in an affluent Parsi family. He is called the 'Father of the Indian Nuclear Programme'. He established the Tata Institute of Fundamental Research (TIFR) and the Institute of Atomic Energy at Trombay (now named 'Bhabha Atomic Research Centre' - BARC) in collaboration with the Tata Trusts.

Pro. Panchanan Maheshwari (1904-1966) was a great botanist of India. He did revolutionary work on Plant Embryology and test-tube culture of flowers and embryos (In-vitro Fertilization & Tissue Culture). He wrote the famous book 'An Introduction to the Embryology of Angiosperms' which is taught in universities around the world.

All four statements are correct. 'Ashtanghridaya' written by Vagabhatta contains a detailed description of the eight parts of Ayurveda (Kaychikitsa, Surgery etc.). Isaac Newton gave three laws of motion and the universal law of gravitation in 'The Principia Mathematica' in 1687. In Ayurveda, Charaksamhita, Sushrutasamhita and Ashtangahridaya are considered to be the 'major' texts of Tridosha and medicine. Newton published the book 'Optics' in 1704.

Louis Pasteur (27 December 1822 – 28 September 1895) was a famous French chemist and microbiologist. He gave the Germ Theory of the spread of diseases by microorganisms. He discovered vaccines for rabies and anthrax. In his honor, the method of sterilizing milk by heating it to a certain temperature (63°C for 30 minutes or 72°C for 15 seconds) is called 'Pasteurization'.

In the history of mathematics, the calculation of the value of 'Pi' (π) and the formula like Pythagoras theorem was first given by the ancient Indian mathematician Baudhayana in his 'Shulba Sutra'. Later, the great astronomer and mathematician Aryabhata propounded the exact value of Pi to be 3.1416 to four decimal places.

Transmission of heat in solid substances mainly occurs by conduction method, in which the particles of the substance vibrate in their place and transfer heat further. Metals (like steel, copper) are good conductors of heat, whereas wood, plastic and glass are poor conductors of heat. Therefore, heat cannot flow through conduction in the wooden spoon and the other end does not cool down. On the contrary, when a steel spoon is put in hot milk, it gets heated by conduction.

In the desert, the sand becomes extremely hot during the afternoon, due to which the air in contact with the surface gets heated and becomes rare (low density and low refractive index), while the air above becomes cold and dense. When light rays coming from trees or sky enter denser to rarer layers of air, they move away from the normal. Ultimately when the angle of incidence exceeds the critical angle, 'Total Internal Reflection' occurs and the rays reach the viewer's eyes, causing an inverted reflection and the illusion of water.

The universally accepted rule of chemistry is 'like dissolves like'. Water is a polar solvent in which hydrogen bonding occurs, whereas oil and fat molecules are non-polar. Therefore, there is no chemical attraction between oil and water and they do not mix with each other. Also, the density of oil (about 0.9 g/cm³) is less than the density of water (1.0 g/cm³), so oil floats on the surface of water.

All four statements are correct. Surface tension is the tendency of a liquid due to which its free surface tries to occupy minimum area. The reason for this is the cohesive force between the molecules of the same substance. The spherical shape of raindrops is an example of surface tension because the surface area of ​​a sphere is minimum. When soap is dissolved, the surface tension decreases due to which the solution reaches the fine fibers of the cloth. On heating, the surface tension of liquids decreases, due to which hot soup spreads better on the taste buds of the tongue.

All options are practical examples of capillarity. A glass tube with fine diameter is called a capillary. The surface tension of the liquid causes the liquid to rise or fall in the capillary. Microscopic capillaries in the soil prevent water from evaporating below, so farmers break the capillaries by plowing after rain to retain moisture. The movement of water from the roots of plants to the leaves and the melting of wax from the thread in a candle are also examples of capillarity.

According to Archimedes' Principle, a piece of ice floating in water displaces water equal to its total weight. When ice melts, the volume of melted water is exactly equal to the volume of water displaced that was occupied by the ice. Hence the level of water in the glass or vessel remains exactly the same (unchanged).

When water freezes, the intermolecular space increases due to hydrogen bonding in its crystalline structure, due to which its volume increases and the density decreases to about 0.92 g/cm³ compared to water (1 g/cm³). According to the law of buoyancy, since the density of ice is 9/10 that of water, 90% of it (9/10) remains submerged inside water and only 10% of it (1/10) is visible outside the surface of the water.

Due to the force of gravity on the earth, the flame of the candle points upwards due to the rising of hot and light gases and the coming down of cold heavy air (convection currents). But in the state of weightlessness, convection currents do not arise due to zero gravitational force. Hence the gases spread evenly all around and the shape of the candle flame becomes spherical.

The formula for excess pressure inside a soap bubble is P = 4T/R, where T is the surface tension and R is the radius (half the diameter of the radius). It is clear from this formula that the air pressure inside the bubble with small radius (small diameter) is more and the air pressure is less in the big bubble. When the tube is opened, air flows from higher pressure (smaller bubbles) to lower pressure (larger bubbles), causing the smaller bubble to become smaller and the larger bubble to become larger.

Objects appear to be of the color of light they reflect. Chlorophyll pigment present in leaves reflects green light and absorbs other colors (blue, red) to make food. A cut is made in the nib of a fountain pen which acts like a microscopic capillary, and due to surface tension, ink continuously flows to the nib due to the principle of capillarity.

When a non-volatile solute like salt is added to water, the vapor pressure of the solvent decreases. To bring the vapor pressure equal to the atmospheric pressure, water has to be heated to a higher temperature, due to which the boiling point increases (Boiling Point Elevation). On the other hand, by adding impurities the freezing point of water falls below 0°C (Freezing Point Depression). For this reason, 'Freezing Mixture' is made by mixing salt in ice, which is used in making kulfi/ice cream.

The speed of sound waves depends on the elasticity and density of the medium. The speed of sound is highest in solids (about 5960 m/s in steel), medium in liquids (about 1480 m/s in water) and lowest in gases (343 m/s in air). When the hammer is struck, the first sound reaches faster through the steel track first and the second sound reaches later through the air medium, due to which the boy hears the sound twice.

While turning, the cyclist requires 'centripetal force' (F = mv²/r) required for circular motion. As he leans towards the center of the turn, the component of his weight and the reaction force of the road provides the required centripetal force. The machine for extracting butter by squeezing milk or curd works on the principle of 'Centrifugal Force', which is a virtual pseudo force acting outward in circular motion.

Wooden doors swell due to 'imbibition', the process by which the colloidal particles of dry wood absorb the atmospheric moisture of the rainy season without dissolving it. Clouds in the sky are made up of extremely tiny water droplets and ice particles. Due to the viscosity of air, the value of terminal velocity of these microscopic particles is very low and due to their density being less than the density of air, they appear to float.

A refrigerator is a heat pump that extracts heat from the food inside and releases it into the room air. When the refrigerator door is kept open, the temperature sensor inside it keeps the compressor running continuously. The compressor absorbs heat from the air of the room and then adds mechanical/electrical heat generated by the operation of the compressor and releases it back into the same room. As additional heat is added to this closed cycle, the temperature of the room gradually increases.

While climbing a slope or a mountain, the human center of gravity shifts further compared to the plain. Therefore, to maintain balance and increase stability, the person bends forward. Due to the steam not coming out inside the pressure cooker, the pressure becomes almost double the atmospheric pressure. Due to increase in pressure, the boiling point of water increases from 100°C to about 120°C, due to which the food gets more heat and the food gets cooked faster.

The temperature of boiling water of 100°C and steam of 100°C is the same, but to convert water of 100°C into steam of 100°C, 536 calories of heat per gram is required, which is called 'Latent Heat of Vaporization'. When the steam comes in contact with the skin, it condenses into water at 100°C and this gives an additional 536 cal/g of latent heat to the skin, causing severe burning.

According to Bernoulli's Principle, where the velocity of an ideal fluid or gas is high, the pressure decreases. When a strong storm occurs, air flows over the roof at a very high speed, due to which the atmospheric pressure above the roof becomes very low. Whereas the air pressure inside the room under the roof remains normal (high). Due to this pressure difference, a resultant force is applied from bottom to top which uproots the tin or thatched roof and blows it away.