Explanation

Explanation

AUTHENTIC means مستند

Genuine means حقیقی

Explanation

The phenomenon where a chemical element exists in multiple crystalline forms is called allotropy

Allotropy refers to the ability of an element to exist in two or more different forms in the same physical state.

This is different from polymorphism, which is a broader term referring to any substance (not just elements) that can exist in multiple crystalline forms. 

Explanation

• Phosphorus (P), Potassium (K), and Nitrogen (N) are three essential macronutrients for plant growth.
• It is also referred to as "NPK".
• They play critical roles in various plant processes, including photosynthesis, root development, and cell growth.

Explanation

• The Candela (cd) is the SI unit of luminous intensity.
• It is defined as the luminous intensity of a monochromatic source that emits light at a frequency of 540 x 10^12 Hz with a luminous efficiency of 683 lm/W.

Explanation

The corrected sentence would be: "The teacher is popular with his students."

This means that the students like and admire the teacher.

"استاد اپنے طلباء میں مقبول ہوتا ہے۔"

Explanation

The weight of a man in an elevator descending with an acceleration of 4.9 m/s² will become:

Let:

• Actual weight $W=mg$

• Acceleration due to gravity g=9.8m/s^2

• Acceleration of the elevator a=4.9m/s^2

When an elevator descends with acceleration $a$, the apparent weight becomes:

W′=m(g−a)

Substitute values:

W′=m(9.8−4.9)=m(4.9)
W′=1​/2×mg

So, the apparent weight becomes half of the actual weight.

Explanation

Primary storage, also known as main storage or memory.

It is the area in a computer in which data is stored for quick access by the computer's processor.

The terms random access memory (RAM) and memory are often as synonyms for primary or main storage.

Explanation

The formula for calculating the density of an ideal gas is d = PM/RT, where: 

• d: is the density of the gas
• P: is the pressure of the gas
• M: is the molar mass of the gas
• R: is the ideal gas constant
• T: is the temperature of the gas in Kelvin

The ideal gas law is expressed as PV = nRT, where 'n' is the number of moles.

Density (d) is mass (m) divided by volume (V), so d = m/V.

We can relate the number of moles (n) to mass (m) and molar mass (M) using n = m/M.

Substituting this into the ideal gas law, we get PV = (m/M)RT.

Rearranging the equation to solve for density (d = m/V), we get d = PM/RT. 

Explanation

In a food chain, herbivores are primary consumers, feeding on producers (plants), which places them at the second trophic level.

The first level is occupied by plants (producers), and herbivores come next.