Physics and Measurement
Physics and Measurement PDF Notes, Important Questions And Synopsis
Physics and Measurement PDF Notes, Important Questions and 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:
Nuclear force (weak)
Very short, sub-nuclear size
Nuclear force (strong)
Short, nuclear size
- Physical quantities:
Measure of physical quantity (Q) = numerical value of physical quantity (n) × size of unit (u) n1u1 = n2u2 = constant
Fundamental quantities, SI unit and their symbols:
Amount of substance
- 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 M1, L1 and T1 and in another system are M2, L2 and T2,
- 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 are classified as (i) systematic errors and (ii) random errors.
- If x1, x2, x3 … 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
JEE Main Video Lectures By ExpertsVIEW ALL
Units and MeasurementThis video explains the international unit system, parallax method of measuring large distances and estimating the diameter of a molecule.
Electric Charge - Part 1This video describes the concept of charge, conductors and insulators, and methods of charging insulators.
Units and MeasurementThis video explains significant figures, rules to identify significant figures and rounding off uncertain digits.
Gold Leaf Electroscope - Part 1This video explains the basic properties of electric charges.
Coulom's Law of Electric Force - Part 1This video describes Coulomb's law to calculate the force between any two point charges and the comparison between Coulomb's law and Newton's law of gravitation.
Motion in a Straight LineThis video explains the calculation of displacement and average velocity of an object.
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- Laws of Motion
- Work, Energy and Power
- Rotational Motion
- Properties of Solids and Liquids
- Kinetic Theory of Gases
- Oscillations and Waves
- Current Electricity
- Magnetic Effects of Current and Magnetism
- Electromagnetic Induction and Alternating Currents
- Electromagnetic Waves
- Dual Nature of Matter and Radiation
- Atoms and Nuclei
- Electronic Devices
- Communication Systems