Everyday Science

Fiber helps in preventing constipation by adding bulk to the stool and facilitating its passage through the digestive tract, thus promoting regular bowel movements.

Among the given substances, sugar (sucrose) is the most soluble in water, with a solubility of about 211 grams per 100 mL at 25°C. Common salt (sodium chloride) is also highly soluble but less so than sugar, dissolving about 35.7 grams per 100 mL at 25°C. Camphor and sulfur have very low solubility in water, with camphor around 0.7 grams per 100 mL and sulfur essentially insoluble. Therefore, sugar is the most soluble substance in water among the options.

Water reaches its maximum density and minimum volume at 4°C due to the unique hydrogen bonding in water molecules, which causes it to expand upon freezing and contract as it warms to 4°C.

Gales are defined as strong winds with speeds typically between 50 and 88 km/h. Among the given options, 55 km/h best fits the lower threshold for gale-force winds, making option B correct.

The temperature of the Sun is approximately 6000ºC. Converting Celsius to Fahrenheit using the formula F = (C × 9/5) + 32 gives F = (6000 × 9/5) + 32 = 10832ºF, which matches option C.

Hydrogen gas is used in the manufacture of Vanaspati Ghee through a process called hydrogenation, where hydrogen is added to vegetable oils to convert them into semi-solid fats.

Vitamin C deficiency causes scurvy, a disease characterized by bleeding gums, weakness, and bruising. The other options are caused by deficiencies of different vitamins or nutrients.

Aviation fuel for jet airplanes is primarily kerosene-based because it has suitable combustion properties and energy content for jet engines, unlike petrol, gasoline, or diesel.

Vitamin C is essential for the growth and repair of tissues because it helps in the synthesis of collagen, an important protein for skin, cartilage, tendons, ligaments, and blood vessels.

Pellagra is a disease caused by niacin (vitamin B3) deficiency and primarily affects the skin, causing dermatitis along with other symptoms. The other options affect bones or blood but not the skin.

The pink color in onions is due to the presence of anthocyanins, which are water-soluble pigments responsible for red, purple, and pink colors in many plants.

Adding sugar to water causes boiling point elevation because sugar molecules disrupt the formation of vapor, requiring a higher temperature to boil the solution.

Vitamin D is chemically known as Calciferol. Retinol is vitamin A, and Tocopherol is vitamin E, so option B is correct.

Radiations are harmful primarily because they alter body tissues at the cellular level, which can lead to various health issues including cancer. While radiation can cause skin cancer, the broader and more accurate harm is the alteration of body tissues.

One gross is a unit of quantity equal to 12 dozen, which is 144 items. Therefore, option C (12 Dozen) is correct.

Nicolaus Copernicus proposed the heliocentric model, demonstrating that the Earth is not the center of the universe, replacing the earlier geocentric model supported by Aristotle.

Graphite is commonly used as a dry lubricant due to its layered structure, which allows layers to slide over each other easily. Silica, diamond, and iron oxide are not typically used as lubricants.

Among the given liquids, mercury is the best conductor of heat due to its metallic nature, whereas water, ether, and alcohol have much lower thermal conductivity.

Milk is composed mostly of water, typically around 87%, which makes option C the correct answer. This high water content is why milk is considered a good source of hydration.

Corona disease, caused by the coronavirus, is an infectious disease because it spreads from person to person through respiratory droplets.

Galvanizing is the process of coating iron or steel with zinc to protect it from rusting. Zinc acts as a sacrificial metal, preventing corrosion of the underlying iron.

Crude oil is a natural source of hydrocarbons formed from the remains of ancient marine organisms, making it the primary natural source of hydrocarbons. Biomass and carbohydrates are organic but not primarily hydrocarbon sources, and coal is a carbon-rich fossil fuel but not classified as a hydrocarbon source like crude oil.

The Earth's atmosphere is primarily composed of nitrogen, which makes up about 78% of the atmosphere by volume, making it the principal constituent. Oxygen is the second most abundant gas, but not the principal one.

Temperature is a measure of the average kinetic energy of particles in a substance, not a form of energy itself. Heat, light, and electricity are all forms of energy.

Ethylene gas is commonly used for artificial ripening of green fruits because it acts as a natural plant hormone that triggers the ripening process.