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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