An excited atom can return to its ground state by absorbing electromagnetic radiation is false about the electromagnetic radiation.
Option B
<u>Explanation</u>:
In the scope of modern quantum theory, the term Electromagnetic radiation is identified as the movement of photons through space. Almost all the sources of energy that we utilize today such as coal, oil, etc are a product of electromagnetic radiation which was absorbed from the sun millions of years ago.
Various properties of electromagnetic radiations are a directly proportional relationship between the energy and the frequency, Inverse proportionality between frequency and the wavelength, etc. Hence, we can conclude that an "excited atom" can never return to its ground state by assimilating electromagnetic radiation and the 2nd statement is false.
Diameter of objective lens = 1.22m
Wavelength of light = 4000Å
We have to find resolving power of telescope ..
★ Resolving power of telescope is given by
RP = D/1.22λ
- D denotes diameter of lens
- λ denotes wavelength of light
RP = D/1.22λ
RP = (1.22×10⁷)/(1.22×4)
RP = 0.25 × 10⁷
RP = 2.5 × 10⁶
★ Resolving power of microscope is given by
RP = 2μsinθ/λ
Answer:
B. Stages are continuous and gradual.
Explanation:
Given :
The ball of a ballpoint pen is 0.5 mm in diameter and has an ASTM grain size of 12.
To Find :
How many grains are there in the ball?
Solution :
Volume of ball of the ballpoint is :
Now, grain size of 12 has about 520000 grains/mm³.
Therefore, number of grains are :
