Topic: Physical World (Test 5)



Topic: Physical World
Q.1
Wave picture of light failed to explain.
A. the photoelectric effect
B. diffraction of light
C. interference of light
D. polarization of light
Answer : Option A
Explaination / Solution:

If light were strictly a wave, the energy in the light would be represented by the amplitude of the light wave. A more intense light source, even if it was light of a lower frequency, would have enough energy to knock electrons away from their molecular orbits, which is necessary to generate a photoelectric current. What actuall occurs is that light below a certain threshold frequency does not generate any current, no matter how intense the light is. Even though the total light energy hitting the photoelectric cell may be high, it cannot free electrons.

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Q.2
The microscopic domain of physics deals with
A. the constitution and structure of matter at the scales of stars and planets and their interaction with different elementary particles
B. None of these
C. The constitution and structure of matter at the scales of atoms and nuclei and their interaction with different elementary particles
D. the constitution and structure of matter at the scales of atoms and nuclei and their interaction with different bodies on the earth
Answer : Option C
Explaination / Solution:

Microscopic domain includes atomic,molecular and nuclear phenomena. It can be said as the study of matter.It includes the study of structure and configuration of atom,nucleus and the constitute particles of atom-electron,proton,neutron and interaction with elementary particles like electron,photon etc.

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Q.3
The microscopic domain of physics deals with
A. the constitution and structure of matter at the scales of stars and planets and their interaction with different elementary particles
B. None of these
C. The constitution and structure of matter at the scales of atoms and nuclei and their interaction with different elementary particles
D. the constitution and structure of matter at the scales of atoms and nuclei and their interaction with different bodies on the earth
Answer : Option C
Explaination / Solution:

Microscopic domain includes atomic,molecular and nuclear phenomena. It can be said as the study of matter.It includes the study of structure and configuration of atom,nucleus and the constitute particles of atom-electron,proton,neutron and interaction with elementary particles like electron,photon etc.

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Q.4
Proper framework for explaining microscopic phenomena is
A. Theory of relativity
B. Classical physics
C. Quantum Theory
D. Maxwell’s theory
Answer : Option C
Explaination / Solution:

Quantum mechanics (QM -- also known as quantum physics, or quantum theory) is a branch of physics which deals with physical phenomena at nanoscopic scales where the action is on the order of the Planck constant. It departs from classical mechanics primarily at the quantum realm of atomic and subatomic length scales.

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Q.5
What is central to the growth of physics?
A. Conjectural descriptions
B. Qualitative descriptions
C. Speculative descriptions
D. Quantitative measurement
Answer : Option D
Explaination / Solution:

Quantitative measurement is central to the growth of physics because Laws of nature happen to be expressible in more precise mathematical equations.

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Q.6
The basic laws of physics are universal means
A. he same laws do not apply on mars and stars
B. the same laws apply in similar contexts
C. the same laws apply in widely different contexts
D. he same laws apply in different continents
Answer : Option C
Explaination / Solution:

Laws of nature as expressed in physics as laws and theories are often said to be universal. This means that, so far as we have been able to test them, they apply everywhere and at every time, past, present and future.

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Q.7
Scientists strategy in general is to
A. Focus first on the complex features of a phenomenon and add its less significant aspects from the start
B. keep building complicated theories
C. Focus first on the essential features of a phenomenon and remove its less significant aspects.
D. Focus first on the complex features of a phenomenon and remove its less significant aspects
Answer : Option C
Explaination / Solution:

It is not practical to take into account all the complexities of a phenomenon in one go. A good and scientific strategy is to focus first on the essential features, discover the basic principles and then introduce corrections to build a more refined theory of the phenomenon by removing its less significant aspects.

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Q.8
To get the law of free fall under gravity, it is better
A. none of these
B. to create a real world experiment of feather and stone
C. to create a situation where in the air resistance is not negligible
D. to create a situation where in the air resistance is negligible
Answer : Option D
Explaination / Solution:

In ohysics, we can neglect some small forces, quantities and calculation.

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Q.9
Unification in physics refers to
A. Explaining by using dissimilar but theories having something in common
B. Unifying competing theories by compromises
C. Explaining by giving a unique theory for each new phenomenon
D. Explaining diverse physical phenomena in terms of a few concepts and laws
Answer : Option D
Explaination / Solution:

Unification is the act of unifying the different laws valid for different phenomena in to a single theory that explains all the different phenomena.

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Q.10
Which of the following is not a synonym of axiom
A. basis
B. assumptions
C. model
D. postulate
Answer : Option C
Explaination / Solution:

An axiom or postulate is a statement/assumption that is taken to be true, to serve as a premise or starting or base point for further reasoning and arguments.

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