Topic: Physical World (Test 4)



Topic: Physical World
Q.1
The law of conservation of energy is.
A. is valid only for Newtonian mechanics
B. thought to be valid across all domains of nature, from the microscopic to the macroscopic
C. is valid only for relativistic mechanics
D. is valid only for applied mechanics
Answer : Option B
Explaination / Solution:

The law of conservation of energy is thought to be valid across all domains of nature, from the microscopic to the macroscopic. It is routinely applied in the analysis of atomic, nuclear and elementary particle processes. At the other end. all kinds of violent phenomena occur in the universe all the time. Yet the total energy of the universe (the most ideal isolated system possible!) is believed to remain unchanged.

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Q.2
Physics is a
A. Applied Science
B. Mathematical Science
C. Natural Science
D. Engineering Science
Answer : Option C
Explaination / Solution:

The natural sciences seek to understand how the world and universe around us works. There are five major branches (top left to bottom right): Chemistry, astronomy, earth science, physics, and biology.

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Q.3
The word Science originates from the Latin verb Scientia meaning
A. to see
B. to know
C. to experience
D. to observe
Answer : Option B
Explaination / Solution:

The phrase "scientia potentia est" (or "scientia est potentia" or also "scientia potestas est") is a Latin aphorism meaning "knowledge is power"

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Q.4
The scientific method is
A. a body of techniques for investigating phenomena, acquiring new knowledge...
B. A procedure for proposing new hypothesis
C. a prescribed method for investigating phenomena, acquiring new knowledge..
D. A method for proposing new theories.
Answer : Option A
Explaination / Solution:

The scientific method is a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry is commonly based on empirical or measurable evidence subject to specific principles of reasoning.

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Q.5
Which of the following is a possible first step in applying the scientific method
A. Formulation of a question
B. Building a theory
C. Formulating a hypothesis
D. Conducting tests
Answer : Option A
Explaination / Solution:

The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why, or Where? For a science fair project some teachers require that the question be something you can measure, preferably with a number. Add image of question 16686

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Q.6
Which of the following is a possible final step in applying the scientific method
A. Building a theory
B. Formulation of a question
C. Analysis of test results
D. Formulating a hypothesis
Answer : Option C
Explaination / Solution:

Your experiment tests whether your prediction is accurate and thus your hypothesis is supported or not. It is important for your experiment to be a fair test. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same. You should also repeat your experiments several times to make sure that the first results weren't just an accident.

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Q.7
A scientific theory is accepted if
A. The theory is approved by a panel of people after studying the theory only
B. The theory is very simple elegant or very complicated
C. predictions of the theory are confirmed by experiments
D. The theory is derivable from other theories logically.
Answer : Option C
Explaination / Solution:

A scientific theory is an explanation of some aspect of the natural world that can, in accordance with the scientific method, be repeatedly tested, using a predefined protocol of observations and experiments.Established scientific theories have withstood rigorous scrutiny and are a comprehensive form of scientific knowledge.

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Q.8
A scientific theory
A. is changed to suit new fashion among scientists
B. is fixed once and for all because it is logical
C. cannot be changed but can be reformulated
D. can be revised if required to fit new phenomenon or data
Answer : Option D
Explaination / Solution:

A scientific theory is not the end result of the scientific method; theories can be proven or rejected, just like hypotheses. Theories can be improved or modified as more information is gathered so that the accuracy of the prediction becomes greater over time.

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Q.9
Heliocentric theory proposed by Nicolas Copernicus was
A. replaced by parabolic orbits to fit the data better
B. replaced by elliptical orbits to fit the data better
C. replaced by elliptical orbits to fit the taste of new rulers of Italy
D. replaced by circular orbits to fit the data better
Answer : Option B
Explaination / Solution:

Copernican heliocentrism is the name given to the astronomical model developed by Nicolaus Copernicus and published in 1543. It positioned the Sun near the center of the Universe, motionless, with Earth and the other planets rotating around it in circular paths modified by epicycles and at uniform speeds. This theory was replaced by Keplar. All planets move in elliptical orbits, with the sun at one focus. This is one of Kepler's laws. The elliptical shape of the orbit is a result of the inverse square force of gravity. The eccentricity of the ellipse is greatly exaggerated here.

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Q.10
Newtonian mechanics could not explain
A. fall of bodies on earth
B. Some of the most basic features of atomic phenomena.
C. movement of planets
D. flight of rockets
Answer : Option B
Explaination / Solution:

When science progressed into the realm of the microscopic, of dimensions the size of an atom, i.e. less than a nanometer, it was observed that newtonian mechanics and classical electrodynamics were in contradiction with experiments, could not explain them. At the microscopic level, forces don't have a meaning, because nothing touches directly anything else. There are intermediate force carriers of what is perceived as "force" macroscopically.

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