Everyday Science

Most meteors burn up in the mesosphere due to friction with atmospheric particles, preventing them from reaching the Earth's surface.

Oxalic acid solution is commonly used to remove rust stains from cloth because it reacts with the iron oxide (rust) and helps dissolve it, making it easier to wash out. Alcohol and kerosene oil are not effective for removing rust stains.

Permanent hardness in water is caused by dissolved salts like calcium sulfate and magnesium sulfate, which cannot be removed by boiling. Adding washing soda (sodium carbonate) precipitates these salts, thus removing permanent hardness.

The troposphere is the lowest layer of Earth's atmosphere where most weather phenomena occur. It lies below the stratosphere, mesosphere, and thermosphere.

A1C measures the average blood sugar level over the past two to three months by assessing the percentage of glycated hemoglobin in the blood, making option B correct.

Lingxi-03, developed by Galaxy Space, was launched using the Long March-3D carrier rocket, which is a commonly used Chinese launch vehicle for such satellites. The other options are either incorrect or non-existent rockets.

Milk is a rich source of Vitamin B-12, which is primarily found in animal-based foods. Cashew nuts, apples, and watermelon do not contain significant amounts of Vitamin B-12.

Convex lenses are used in microscopes because they converge light rays to form a magnified image of small objects, which is essential for microscopic observation. Concave lenses diverge light and are not used for magnification in microscopes.

As comets approach the sun, the heat causes the ice to sublimate, releasing gas and dust into space, forming the comet's coma and tail. This process is accurately described by option B.

The extremely cold temperatures in the Moon's polar regions preserve materials by slowing down chemical and physical changes, effectively acting as a 'time capsule' that maintains the state of objects over long periods.