9th Class Physics Chapter 9 Long questions
9th Class Physics Chapter 9 Long questions.
9.1 What are the main branches of Physics? State briefly.
1) Mechanics :-
It is the study of motion.
2) Acoustics :-
it the study of audible sound energy.
3) Optics :-
It is the study of visible light.
4) Electromagnetism :-
It is the study of electromagnetic phenomena.
5) Quantum Mechanics :-
It is the study of particles at atomic and subatomic level.
6) Relativistic Mechanics :-
It explains how space and time are not absolute quantities but related to observer.
7) Nuclear Physics :-
It is the study of properties of nuclei of atoms.
8) Particle Physics :-
It is the study of subatomic and elementary particles.
9) Astronomy :-
It is the study of distribution of celestial bodies like planets and starts.
10) Cosmology :-
It tells us about the large structure and evolution of universe.
11) Solid State Physics :-
It is the study of properties of matter in solid form.
12) Biophysics :-
Some biological systems and processes are described using principles and techniques of physics under this field of study.
13) Medical Physics :-
It applies physical principles to develop techniques and technologies for health diagnosis and treatment.
14) Astrophysics :-
It deals with the physical properties and processes of celestial bodies and phenomena.
15) Geophysics :-
It applies physical principles to the study of internal internal structure of Earth.
16) Climate Physics :-
It includes the study of physical processes in the environment.
17) Computation Physics :-
it is about the use of computational techniques and methods to solve complex physical problems.
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9.2 What is meant by interdisciplinary fields of Physics? Give three examples.
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9.3 What is scientific method? Describe its main steps with examples.
Scientific method is a scientific approach used to search for truth of an issue and problem solving regarding natural and physical word.
Lets check its main step with examples
1:- Observation
Careful watching and noting of phenomena or events.
For example plants near sunlight grow faster.
2:- Identification
After observation, we form a question
Does sunlight affect the growth of plant ?
3:- Hypothesis
A possible answer of the question.
Plants grow faster when they receive more sunlight.
4:- Experiment
We do experiments to test the hypothesis
We grow two plants. One in the sunlight and one in the shaded area and then compare their growth.
5:- Theory
A theory is a well tested explanation after repetition of experiments.
Theory explains how sunlight helps plants to grow.
6:- Prediction
A statement of what should happen if the theory is correct.
A plant receiving more sunlight will grow taller.
7:- Falsifiability
A scientific idea must be capable of being proven false by experiment.
If shaded plant grows taller, the idea is falsified.
8:- Scientific Law
A scientific law describes the natural relationship.
Plants grow faster with more sunlight.
Ohm’s law, law of inertia and law of conservation of energy are also a scientific laws.
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9.4 Differentiate the terms, science, technology and engineering with examples.
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9.5 What is the scope of Physics in everyday life? Give some examples.
Physics is a fundamental science. Scope of Physics in everyday life is vast because it tells us how the universe works. Physics is not limited to labs.
1) Medical applications:-
Physics is essential in medical technology for example X-rays and MRI.
2) Magnetism:-
Magnets and magnetic materials are used in daily life for example credit card chips and motors.
3) Sound:-
Physics tells us how sound is produced for example microphones and speakers.
4) Heat:-
Physics tells us about the phenomena of heat and temperature for example air conditioners and heaters.
5) Transport:-
Physics tells us about rest and motion for example a moving car and a rocket.
6) Electricity:-
Physics tells us how electricity flows for example phones and computers.
7) Light:-
Physics tells us how light travels for example camera and microscopes.
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Some important links are given below
