9th Class Physics Notes “2nd Conceptual Question”

Q1: How physics play a crucial role in science technology and society?

Ans: Role of physics in science technology and society:

Physics is the root of every field of science. Most of the major developments in chemistry, biology, geology, astronomy, and even in medicine has been made by physicists.

Role of physics in science and technology:

The use of physics in information technology has improved the standards of communication. Mobile phones, including the development of the internet, have benefited from physics research in telecommunication from radio waves to fiber optic cables.

Cathode ray oscilloscope (CRO) is the invention of physics which can be used as a graph plotting device. CRO use in T-V circuit.

Role in society:

The use of basic laws of physics is common in our daily life, from the colds refrigerator to the hottest furnace, from the lowest ship to the fastest plane, from the shape of finest thumb pin to the huge missile airplane and spacecraft, law and principle of physics are very important.

Physics has a very important role in generation of energy. Nowadays, electrical energy requirement for all developing nations physics allow generating electrical energy from different sources.

Physics is involved in medical diagnostic techniques, such as X-rays, magnetic resonance imaging (MRI), and ultrasonic blood flow measurement. Medical therapy sometimes directly involves physics.

Q: Differentiate between Base and Derived physical quantities?

Base physical quantities Derived physical quantities

1. Definition: All those quantities in terms of which other 1. Definition: Those quantities which are obtained by physical quantities are expressed. multiply and dividing one base quantities with other.
2. Number: Base physical quantities are Seven in number 2. Number: Derived physical quantities are more than seven.
3. Simple and prominent: The base physical quantity are simple and Derived physical quantities are complex. prominent. obtain by multiply and dividing of base physical quantities.
4. Unit: Then unit of base physical quantity are called 4. Unit: The unit of derived physical quantities are base unit. called derived unit.
5. Example: Length, mass, temp etc 5. Example: Force, Torque, velocity, speed.