Explanation

 Volume is a scalar quality.

It is a physical quantity that measures the amount of three-dimensional space

Occupied by matter and is completely described by its magnitude alone, unlike vectors which also have direction. 

Explanation

Reflecting telescopes primarily use concave mirrors to collect and focus light.

While some designs might incorporate a plane mirror for specific purposes, the key component is the concave mirror.

In more complex designs like the Cassegrain telescope, a secondary convex mirror is added to further focus the light onto the eyepiece. 

Explanation

When white light shines on a green leaf, the chlorophyll pigment in the leaf absorbs most wavelengths of light except for green.

The green light is reflected, making the leaf appear green to our eyes. 

Explanation

Quarks are the smallest known particles in the universe.

They are the building blocks of protons and neutrons, which make up atomic nuclei.

They were discovered in the 1960s. 

They are considered the most fundamental units of matter.

Explanation

To kill bacteria in a filtration plant, chlorine is used.

This process, known as chlorination, is one of the most common methods of water disinfection. 

Chlorine is effective because it:

Kills or inactivates disease-causing microorganisms, such as bacteria, viruses, and parasites.

It is relatively inexpensive and easy to apply.

While other methods like ozone and ultraviolet (UV) light are also used for disinfection

Explanation

• On Earth, surface water covers 70% area.
• 70-71 percent of the Earth's surface is water-covered.
• The oceans hold about 96.5 percent of all Earth's water.
• ***
• This includes oceans, rivers, lakes, glaciers, and groundwater.
  

Explanation

Explanation

Helical gear, more commonly known as double helical or herringbone gears.

This design cancels out the axial thrust forces that typically put a load on the shaft. 

Explanation

Frictional force is directly proportional to the normal force, which for a horizontal surface is equal to the weight of the body.  

So, if the weight increases, the friction also increases.

- Friction ∝ Normal Force (Weight on horizontal surface)

Explanation

Convection is the transfer of heat through the movement of a fluid, and only liquids and gases can flow freely, allowing for the movement of heat currents. 

Additional information:

Solids and gases:

While solids can transfer heat through conduction, they cannot convect because their particles are fixed in place and cannot move freely. 

Liquids and solids:

Convection only occurs in liquids and gases. Solids do not convect due to their fixed particle structure. 

All states of matter:

Convection is specifically related to the movement of fluids, which excludes solids.