Physical World - Online Test

Q1. Physics is a
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.

Q2. The word Science originates from the Latin verb Scientia meaning
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"

Q3. The scientific method is
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.

Q4. Which of the following is a possible first step in applying the scientific method
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

Q5. Which of the following is a possible final step in applying the scientific method
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.

Q6. A scientific theory is accepted if
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.

Q7. A scientific theory
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.

Q8. Heliocentric theory proposed by Nicolas Copernicus was
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.

Q9. Newtonian mechanics could not explain
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.

Q10. Wave picture of light failed to explain.
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.