Everyday Science

Strong winds pose the greatest risk to air travel as they can cause turbulence, affect aircraft control during takeoff and landing, and lead to dangerous flying conditions. While clouds, rainfall, and fogs can affect visibility and comfort, strong winds have a more direct impact on flight safety.

Gasoline is the primary fuel used in light petrol engines due to its high volatility and suitable combustion properties, making it ideal for light patrol (petrol) engines. The other options are either heavier fuels or not commonly used in such engines.

The drum of a Photostat machine is coated with selenium because selenium is a photoconductive material, which means it conducts electricity when exposed to light, making it ideal for the photocopying process.

A shooting star is actually a meteor, which is a small piece of debris from space that burns up upon entering Earth's atmosphere, creating a bright streak of light. It is not the Sun, a comet, or an asteroid.

The Earth's atmosphere is composed of approximately 78% nitrogen, making option C the correct answer. This is a well-established scientific fact about atmospheric composition.

The Earth revolves around the Sun at an average orbital speed of approximately 29 kilometers per second, which is the widely accepted scientific value.

Venus is hotter than Mercury despite being farther from the Sun because it has a thick atmosphere composed mainly of carbon dioxide, which creates a strong greenhouse effect, trapping heat and raising surface temperatures.

Pure water has a neutral pH of 7, but natural water typically ranges from slightly acidic to slightly basic, commonly between 6.5 and 8.5, depending on dissolved minerals and environmental factors. Therefore, option D correctly reflects the typical pH range of water.

Carbon monoxide is a toxic gas that is hazardous to humans because it binds with hemoglobin in the blood, reducing oxygen transport. Carbon dioxide is not toxic at typical environmental levels, and the options 'Lease particles' appears to be a typo, while 'Carbon particles' are harmful but less directly toxic than carbon monoxide.

Vitamin B-2 is known as Riboflavin. It plays a key role in energy production and the metabolism of fats, drugs, and steroids.