Physical Quantity || Physics || Class 11 || NEB || MeroNote||

Physical quantities: 

All measurable quantities are called physical quantities. For example; mass, length, time, velocity, temperature etc.  

Types of physical quantities: 

There are two types of physical quantities. 

1. Fundamental physical quantity: 

Ans:  The physical quantity which is independent of other physical quantities is called fundamental physical quantity. For example; mass, length, time, temperature etc. 

2. Derived physical quantity:

Ans: The physical quantity which is derived from other physical quantities is called derived physical quantity. For example; velocity, acceleration, force etc. 

Unit: 

Ans: The standard physical quantity taken as reference to express the physical quantity is called unit. For example; kg, meter, ms-1 Newton (N) etc. 

Types of unit: 

1. Fundamental unit: 

Ans: The unit which is independent of other units is known as fundamental unit. For example; kg, m, S. etc.

2. Derived unit: 

Ans: The unit which is derived from other units is known as derived unit. For example; kgm-3, ms-1 etc.

System of unit:

Ans: A system of units is a set of standardized measurements used to quantify physical quantities. Key types include:

SI (International System of Units):

Ans:  The global standard with base units like meter, kilogram, and second.

Imperial System: 

Ans: Used mainly in the US and UK, with units like feet, pounds, and gallons.

CGS (Centimeter-Gram-Second):

Ans:  A metric system based on centimeter, gram, and second.

MKS (Meter-Kilogram-Second):  

Ans: A precursor to SI, using meter, kilogram, and second.