NEET Physics Physics and Measurement
Physics and Measurement PDF Notes, Important Questions and Synopsis
SYNOPSIS
 Physics domain:
 Macroscopic domain: This includes phenomena at the laboratory, terrestial and astronomical scales. Classical mechanics deals with the macroscopic domain.
 Microscopic domain: This includes atomic, molecular and nuclear phenomena. Quantum mechanics deals with the microscopic domain.
 Four fundamental forces of nature:
Force 
Relative strength 
Range 
Gravitational force 
10^{39} 
Infinite 
Nuclear force (weak) 
10^{13} 
Very short, subnuclear size 
Electromagnetic force 
10^{2} 
Infinite 
Nuclear force (strong) 
1 
Short, nuclear size 
 Physical quantities:

Measure of physical quantity (Q) = numerical value of physical quantity (n) × size of unit (u) n_{1}u_{1} = n_{2}u_{2} = constant

Fundamental quantities, SI unit and their symbols:
Fundamental quantity
SI unit
Symbol
Length
metre
m
Mass
kilogram
kg
Time
second
s
Electric current
ampere
A
Temperature
kelvin
K
Amount of substance
mole
mol
Luminous intensity
candela
cd
 Conversion of units:
Consider dimensions of a physical quantity as ‘x’ in mass, ‘y’ in length and ‘c’ in time. If the fundamental units in one system are M_{1}, L_{1} and T_{1} and in another system are M_{2}, L_{2} and T_{2},
then
 Analysis of dimensional correctness:
Every equation should be dimensionally balanced. This is called ‘principle of homogeneity’. The dimensions of each term must be the same on both sides of the equation.  Principle of homogeneity:
According to the principle of homogeneity, dimensions of all terms in a physical expression should be the same.  Errors:
Errors are classified as (i) systematic errors and (ii) random errors.
 If x_{1}, x_{2}, x_{3} … xn are the measured values of quantities in several measurements, then the mean is
 Absolute errors in measured values are
 If the quantity Z is expressed as a product of quantities A and B, then the maximum fractional error in Z is given by
 If Z = AxByCz, then the maximum fractional error in Z is
Videos
 the quantity which is dimensionsless is
 a barometer record 700 mmHg pressure when the atmospheric pressure is 720 mmHg and the barometer records 720 mmHg pressure when the atmospheric pressure is a 750 mmHg what should be the atmospheric pressure when parameter records 750 mmHg
 What is percentage error in 9.89 gram?
 plz solve this proper explanation...
 pls explain this
 Answer is option 3 plz explain... Thanks!
 Answer this question..thanks!
 what is fundamental quantity.
 which clock maintains the indian standard time? The jiffy is a prime example of a nonstandard unit of measurement of  .
 dimension of linear momentum
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