# class 11 physics notes units and measurements

There are certain physical quantities which are very fundamental in nature. Unit and Measurement Handwritten Notes for 11 Physics CBSE Board Exam are very important exam and it need lot of Hard-work and Knowledge to score good marks in these exam. var today = day + "-" + month + "-" + now.getFullYear(); [\mu ] = {{\left[ {\Delta F} \right]\left[ {{r^2}} \right]} \over {\left[ {{i_1}\Delta {l_1}} \right]\left[ {{i_2}\Delta {l_2}} \right]}} = {{ML{T^{ - 2}}{L^2}} \over {IL\,IL}} = {\rm{ }}ML{T^{ - 2}}{I^{ - 2}}. The concepts in Class 11 Physics Chapter 2 notes are explained so clearly that it takes no time to understand them. The dimensions of fundamental quantities are expressed as (i) that of length by L, (ii) that of mass by M, (iii) that of time by T, (iv) that of current by I, (v) that of  temperature by (K). Like the video? \left[ G \right] = {{\left[ F \right]\left[ {{d^2}} \right]} \over {\left[ {{m_1}} \right]\left[ {{m_2}} \right]}} = {{ML{T^{ - 2}}{L^2}} \over {MM}} = {\rm{ }}{M^{ - 1}}{L^3}{T^{ - 2}} CBSE class 11 Physics notes Chapter 2 is prepared by our experts as per the latest syllabus and exam pattern Class 11 Physics. } v = k{r^{ - 1}}{\rho ^{ - 1}}{\eta ^{ 1}} or v = {{k\eta } \over {r\rho }}, Very awesome and fantastic note I really like it, thank you it was very helpful for my studies, Very simple and in perfect way of writing note ,it will support us greatly *thank you so much*, This is very nice notes In mechanics three base units are required. (a)  Invariability (iv) kinetic energy (vi) the candela (cd) - standard of luminous intensity (iii) To determine the exact relation between physical quantities which are likely to be interlinked. Measurement consists of a numeric quantity along with a relevant unit. Units for Fundamental or base quantities (like length, time etc.) Hence c = 1,  b = -1, a = -1 function checkTime(i) { Often derived units are given names. document.write(''); if (i < 10) { The units of these quantities are called base units of the system. and      -c = -1 The ampere (A): This is defined as the constant current which, if maintained in each of two infinitely long, straight, parallel wires of negligible cross-section placed 1 m apart, in vacuum, produces between the wires a force of 2 \times {10^{ - 7}} newton per meter length of the wires. (ii) the kilogram (kg) - standard of mass Some Important derived units (ii) Angle =  {{Distance} \over {Distance}} i.e Angle is dimensionless. The common systems of units are (i) the foot-pound-second (fps) system, (ii) the centimeter-gram-second (cgs) system, (iii) the metre-kilogram second (MKS) system and (iv) the International System of Units (SI). All disputes will be settled in the Apex Court of experiments. (iv) Kinetic energy =  {1 \over 2} Mass \times Velocity2, [Kinetic energy] = [Mass] ´ [Velocity]2 = ML2T-2 (v) constant of gravitation Hello Arya this is our sample video for full video Please call on 9026272829.﻿, Physics Chemistry Mathematics Biology Is this much notes beneficial for class 11, Nice and helpful notes compare to byjuis and extramarks. return i; i = "0" + i; 20 newtons = 2 \times {10^6} dynes. (iii) Density =  {{Mass} \over {Volume}}, [Density] = {{[Mass]} \over {[Volume]}} = {M \over {{L^3}}} = M{L^{ - 3}} The standard unit should be easily made available for comparing with other quantities. (vi) Permeability occurs in Ampere's law of force Any standard unit should have the following two properties: (ii) [R. H. S.] = \sqrt {{{\left[ P \right]} \over {\left[ D \right]}}} = \sqrt {{{M{L^{ - 1}}{T^{ - 2}}} \over {M{L^{ - 3}}}}} = L{T^{ - 1}} Notes CBSE class 11 Physics notes Chapter 2 Units and Measurements contains all the topic as per the syllabus of NCERT. These units are called derived units. or         L{T^{ - 1}} = {L^a}{(M{L^{ - 3}})^b}{(M{L^{ - 1}}{T^{ - 1}})^c} = {M^{b + c}}{L^{a - 3b - c}}{T^{ - c}} If the units of these quantities are defined, the units of all other quantities can be derived from these. Assuming that the critical velocity of flow of a liquid through a narrow tube depends on the radius of the tube, density of the liquid and viscosity of the liquid, find an expression for critical velocity, Class 9 - Science+Maths Video Paper Solutions, Class 10 - Science+Maths Video Paper Solutions, 11+12 - Physics + Chemistry + Mathematics, 11+12 - Physics + Chemistry + Mathematics (IIT), 11+12 - Physics + Chemistry + Biology (NEET), Class 9th and 10th : Foundation for IIT Physics, Class 9th and 10th : Foundation for IIT Chemistry, How to make the best choice: Science vs Commerce vs Arts, How to Study Effectively- 9 Secrets No One Tells, How to prepare for IIT-JEE this summer - Top 7 proven ways. Through common usage, certain multiples and submultiples of the fundamental units have been given names. Symbolically, dimension of a physical quantity is written by putting that physical quantity within bracket such as [A] and it is read as dimension of A. var now = new Date(); F = G{{{m_1}{m_2}} \over {{d^2}}} (v) Constant of gravitation occurs in Newton's law of gravitation Unit of force in cgs = g cm s-2 m = checkTime(m); Players may score points but can never win -, An untested speculation for the status of, Any hypothesis, law or theory may be challenged by any player at any time. Our handwritten notes make it easy to score good marks in exam. In electricity and magnetism a standard for current is required in addition to the three base units of mechanics. a - 3b - c = 1 (vii) the mole (mol) - standard of amount of substance. A unit is an internationally accepted standard for measurements of quantities. Assuming that the critical velocity of flow of a liquid through a narrow tube depends on the radius of the tube, density of the liquid and viscosity of the liquid, find an expression for critical velocity. [L. H. S.] = [v] = LT-1   Hence the relation is true. Prefixes, Multiplication Factors and their Units' Names in SI. 3. document.write(''); Physics is a game, physicists are players; the aim is to discover the rules of nature and the playing field is the whole universe. At Vedantu, you will get Units and Measurement Class 11 notes prepared by our subject experts at par with the latest CBSE Syllabus. Check by the method of dimensions whether the following relations are true. \eta = coefficient of viscosity, k is a dimensionless constant and a, b and c are the unknown powers to be determined. var day = ("0" + now.getDate()).slice(-2); [L. H. S.] = \left[ {{{A\,Number} \over {Time}}} \right] = {1 \over T} = {T^{ - 1}} An untested speculation for the status of Rule of Nature is called a hypothesis. Any device - physical, conceptual or computational - may be used. Class ---Class 6Class 7Class 8Class 9Class 10Class 11Class 12IIT-JEEAIPMT/NEET var s = now.getSeconds(); The standard unit must be invariable. Such quantities are called basic or fundamental quantities. A physical law in conjunction with the mechanism of the phenomenon constitutes a physical theory. Dimensions Factors involved in the process of measurement of physical quantity. To measure  a physical quantity we require a standard of measurement. [v] = {[r]^a}{[\rho ]^b}{[\eta ]^c} Each topic is explained in very easy language with colored diagrams. Vedantu provides the best-rated CBSE study materials for all classes. be settled in the Apex Court of experiments. Show Topics. (i) acceleration The metre (m): This is defined as 1650763.73 times the wavelength, in vacuum of the orange light emitted by  in transition from 2p10­  to 5d5. //var today = now.getFullYear()+"-"+(month)+"-"+(day); Hence the result is correct. This standard is called the unit of that physical quantity. Units of all other quantities may be obtained by some combination of the base units. This notes is very nice and in easy language for study. Physics is a game, physicists are players; the aim is to discover the rules of nature and the playing field is the whole universe. what about other topics????? (i) t = 2\pi \sqrt {{l \over g}} . System of units var h = now.getHours(); All disputes will. (v) the kelvin (K) - standard of temperature 2. 6. (ii)  To test the corrections of the results already arrived at To measure a physical quantity we require a standard of measurement.