Explanation

The dielectric constant of water at around 18°C is approximately 80.

This high value makes water an excellent polar solvent for ionic and polar compounds.

Explanation

3% of Earth's water is fresh water.

2.5% of that fresh water is unavailable because it is:

• Locked in glaciers and polar ice caps
• Present in the atmosphere and soil
• Too deep underground to extract affordably

Only 0.5% of Earth's water is available as usable fresh water for human use.

Explanation

The mesosphere is the coldest layer of the atmosphere, with temperatures dropping as low as -90°C.

It lies above the stratosphere and below the thermosphere.

Explanation

They do not perform Baeyer's Test statement is not true because alkynes do perform Baeyer's Test, which detects unsaturation (like double or triple bonds).

In Baeyer's Test, potassium permanganate gets decolorized if alkynes are present, indicating a reaction.

Explanation

A rectifier is an electrical device that converts Alternating Current (AC) into Direct Current (DC).

It works by allowing current to flow only in one direction using diodes.

Explanation

Priestly discover oxygen in 1776.

Oxygen makes up about 46-50% of the Earth's crust by weight, mainly in the form of oxides and silicates.

It is also a major component of water (H₂O).

It is abundant in the atmosphere as O₂.

Explanation

Aristotle is widely considered the founder of meteorology.

He first used the term "meteorology" in the fourth century BC, although his work on weather was based on observation and lore rather than modern scientific methods.

Explanation

The wind is used to produce electricity by converting the kinetic energy of air in motion into electricity.

Wind energy is the energy obtained from the force of the wind.

The unit of wind is: joule

Explanation

"Muhammad Rasool Ullah" begins with a noun, so it is a Jumla Ismia (nominal sentence).

It conveys information, making it Khabria (informative).

Explanation

Hazrat Khadija was the wife of Holy prophet (P.B.U.H).

Hazrat Abu Talib was the uncle of the Holy prophet (p.b.u.h).

Year of sorrow means غم کا سال