Explanation

Couple is not a part of a microscope; it's unrelated terminology in this context.

Stage, Course Adjustment, and Mirror are essential components of a microscope used for holding slides, focusing, and reflecting light, respectively.

Explanation

Attrition is the process where rocks and pebbles grind against each other, causing them to wear down.

It occurs mainly in rivers or along the coast due to movement and collision.

Explanation

According to the Big Bang Theory, all the matter and energy in the universe was initially concentrated in a single point with nearly infinite density.

This point was extremely small, about one nanometer in size, before the universe began expanding.

According to Big Bang Theory, the Universe began about 10-20 billion years ago.

Explanation

Convection is the transfer of heat through the movement of fluids (liquids or gases) due to differences in temperature and density.

It does not occur in solids as the particles in solids are not free to move.

Explanation

The dissolving of salt in water is a physical change because:

Reversible Process: The salt can be recovered by evaporating the water (no new substance is formed).

Molecular Level: Salt (NaCl) dissociates into ions (Na⁺ and Cl⁻) but retains its chemical identity.

Explanation

Phosphorus is used in the match industry, particularly red phosphorus.

It is a key component in the production of matchsticks.

It is highly reactive and helps ignite the match when struck.

Explanation

Bacteria and fungi are decomposers that break down dead plants and animals.

They recycle nutrients back into the ecosystem, maintaining ecological balance.

Explanation

The cochlea is a spiral-shaped organ in the inner ear responsible for converting sound vibrations into nerve signals.

It contains hair cells that detect sound and send signals to the brain via the auditory nerve.

Explanation

Cornea is the transparent, dome-shaped front part of the eye.

It allows light to enter and helps focus it onto the retina.

Explanation

Skin cells form the outermost layer of the body, acting as a protective barrier.

They shield internal organs and tissues from injury, pathogens, and dehydration.