Tag: science & technology

When breathing out, the body does not extract all oxygen from inhaled air. About 16% oxygen remains in exhaled air since humans only absorb about 4-5% of the oxygen they inhale. The options seem confused - if this meant 77% of original oxygen (21% in air), that would be about 16% remaining.

Lactose is the sugar naturally found in milk and dairy products. Glucose is blood sugar, sucrose is table sugar from plants, and fructose is fruit sugar. Lactose is unique to milk as the primary carbohydrate.

The Big Bang Theory states the universe began from a single extremely dense and hot point that expanded rapidly. The Steady-State Theory suggests continuous creation of matter. The other options are not recognized scientific theories of cosmic origin.

Pure water freezes at 32°F (0°C) at standard atmospheric pressure. This is the freezing point where liquid water transitions to solid ice. The other temperatures are incorrect for water's freezing point.

Water boils at 212°F (100°C) at sea level under standard atmospheric pressure. This is the temperature where liquid water transitions to water vapor. The other temperatures are incorrect for water's boiling point at sea level.

An astronomical unit (AU) is the average distance between Earth and Sun, about 93 million miles. A light year is the distance light travels in a year. Parallactic second (parsec) is a unit of interstellar distance. AU is specifically defined by Earth-Sun distance.

India adopted the metric system in 1956 through the Standards of Weights and Measures Act. This standardized measurements across the country. 1947 was independence, 1952 and 1991 are unrelated to metric system adoption.

Ice has very low friction, making it difficult to walk or work on. Friction provides grip between surfaces and our shoes. With minimal friction on ice, we slip easily. Inertia is resistance to motion change, not related to slipping.

Hot air balloons rise because heated air inside is less dense than surrounding cool air. This density difference creates buoyant force (displacement). Less dense fluids rise above more dense fluids. Denser objects would sink, not rise.

The Indian Ocean has an approximate volume of 292,131,000 cubic kilometers, making it the third largest ocean by volume. This figure is based on hydrographic measurements of its basin. The other options are close but not the accepted scientific measurement.