Explanation

Fe3O4 occurs as a mineral with a chemical name Iron (II, III) oxide.

It is also known as Magnetite or Magnetic oxide.

Explanation

Biogas produced as a result of anaerobic decay of organic matter consists primarily of methane (CH4) and carbon dioxide (CO2).

Biogas can also contain small amounts of other gases, such as:

• Water vapor
• Hydrogen sulfide (H2S
• Siloxanes

Explanation

21 March and 23sept equal day and night.

The whole earth experiences equal days and equal nights is called an equinox

In Nairobi (Libya) equal day and night happen.

The shortest day occurs in the Northern Hemisphere is on the 22nd of December

The longest day occurs in the Northern Hemisphere is on 22nd June

Explanation

 Wind speeds of 10–13 kilometers per hour (kph) are considered light breezes.

At this speed, wind may rustle leaves, move small branches, or flutter light flags, but it does not cause damage.

Explanation

Cosmology is the called the study of Universe. 

Edwin Powell Hubble is called the father of Cosmology.

COSMOLOGY means علم کائنات

Explanation

A rectifier is an electrical device that converts alternating current (AC),

which periodically reverses direction, to direct current (DC), which flows in only one direction.

Explanation

Submarines operate based on Archimedes' principle.

It allows them to control buoyancy and submerge or surface by adjusting their density relative to the surrounding water.

Explanation

A calorimeter is an instrument used to measure the amount of heat absorbed or released during a chemical reaction or physical change.

It is essential for studying thermodynamic properties 

Explanation

Cytosine does not form a bond with adenine because its hydrogen bond donors and acceptors are not complementary.

Cytosine typically forms three hydrogen bonds with guanine, whereas adenine forms two hydrogen bonds with thymine.

The patterns of hydrogen bonding in cytosine and adenine do not match, preventing the formation of a stable pair.

Explanation

Conventionally, clockwise torque is taken as negative

because clocks run in a negative direction according to the right-hand rule.

**

Counterclockwise is the positive rotation direction