Question

Assertion
Classical Physics deals mainly with macroscopic phenomena and includes subjects like Mechanics, Electrodynamics, Optics, and Thermodynamics.
Reason
Classical physics is inadequate to handle the microscopic domain and Quantum Theory is currently accepted as the proper framework for explaining microscopic phenomena as it deals with the constitution and structure of matter at the minute scales of atoms and nuclei.
A) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B) Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
C) The assertion is correct but the reason is incorrect
D) Both Assertion and Reason are incorrect

Answer 1

Hint:Classical mechanics is the branch of physics that deals with macroscopic bodies. Classical mechanics failed in explaining many microscopic phenomena. This led to another efficient theory that explained the microscopic phenomenon very well which is quantum theory.

Step by step Solution:
The assertion is correct since classical mechanics deals with macroscopic phenomena. It explains phenomena at Astronomical, laboratory, and terrestrial scales. Therefore subjects like mechanics, electrodynamics, optics, and thermodynamics can be explained using classical mechanics. Classical mechanics mainly use Newtonian mechanics to explain various phenomena at a macroscopic level.

The reason is also correct since when it came to many microscopic phenomena like blackbody radiation, photoelectric effect, Compton Effect, etc. classical mechanics failed to explain. This failure of Classical mechanics raised the need for a new theory that can explain things at a microscopic level. This gave rise to the quantum theory which explains microscopic phenomena very well. All these phenomena can be explained very well using quantum theory.

Since we know that both the assertion and reason are individually correct we need to check whether the reason is the correct explanation for the assertion. From the history of physics, we know that classical mechanics was not enough to explain many microscopic phenomena. This gave rise to Quantum theory that explains things at atomic and nuclear scales.
From the above information, we know that both the assertion and the reason are correct and the reason is the correct explanation for the assertion.

Therefore the correct answer is option (A).

Note:Whenever such kind of a question is asked, read both the assertion and reason carefully. Most of the time it will be implied obviously in the question itself. In this type of question along with your in-depth knowledge about the subject, your verbal ability is also tested. The assertion will be a simple statement and the reason will be the explanation for the assertion. Check the correctness of the assertion and reason separately and then check if the reason is the right explanation for the assertion. Then choose your answer wisely.