Nature of Physical World and Measurement : Multiple choice questions with answers => Nature of Physical World and Measurement : Important Questions UNIT 2 : Kinematics => Kinematics => Concept of Rest and Motion => Types of motion => Motion in One, Two and Three Dimensions => Elementary Concepts of Vector Algebra => Magnitude of a Vector UNITS AND MEASUREMENT 19 t t t t the radius AS = BS so that AB = b = D θ where θ is in radians. Sol: (a, b) Let us first express the relation of pressure with other physical quantities one by one with the help of dimensional analysis. CLASS 11 Physical Education NCERT Question and Solution . The solution spreads over the surface of water forming one molecule thick layer. (c) 163.6 ±2.6 cm2                                   One unified atomic mass unit is approximately the mass of one nucleon (either a single proton or neutron) and is numerically equivalent to 1 g/mol. Q4. We can thus be able to measure the area over which oleic acid spreads. Units of Measurement Physics Class 11 Download in pdf Measurement of physical quantities. 4. You will get here all the important questions with answers for class 11 Physics Chapter Units and Measurement. (c) 1.9 xlO12                                            the dimensions at both side of the equation must be same. Young’s modulus of steel is 1.9 x 1011 N/m2. Like meter is written ‘m’, second as ‘s’, grams as ’g’, etc. J-kg. Which of the following time measuring devices is most precise? Ans:  (a) According to the definition, 1 parsec is equal to the distance at which 1 AU long arc subtends an angle of 1 s. img src=”https://c2.staticflickr.com/4/3939/33180069842_a3d91eac25_o.png” width=”278″ height=”64″ alt=”ncert-exemplar-problems-class-11-physics-chapter-1-units-and-measurements-44″> All questions and answers from the NCERT Book of Class 11 Science Physics Chapter 2 are provided here for you for free. (d) (PR-Q2)/R system the magnitutde of the force is 100 dynes. We have derived the correct relationship between the physical quantities but still the value of dimensionless ‘k’ is unknown. Answer Length of sheet, l = 4.234 m –3. Jan 15, 2021 - MCQ: Units and Measurement - Class 11 Class 11 Notes | EduRev is made by best teachers of Class 11. To answer such questions we need to fix some unit. Q28. Contact us on below numbers. Leading zeros or the zeros placed to the left of the number are never significant. Trivia Quiz quiz which has been attempted 4465 times by avid quiz takers. 2.The length of a pen can be easily measured in cm, the height of a tree can be measured in metres, the distance between two cities can be measured in kilometres and distance between two heavenly bodies can be measured in light year. It is to be noted that these dimensions are not to be confused with three-dimensions of space. Work is said to be perform when a force acts on a body and displaces it through some distance. J. J-kg-1. We have covered all the Class 11 Physics important questions and answers in the worksheets which are included in CBSE NCERT Syllabus. Dimensional analysis has following limitations: 1. Sol: (b, d) Parsec and light year are those practical units which are used to measure large distances. Here the digit to be dropped is 5, then preceding digit is left unchanged, if it is even. Velocity is a derived quantity resulting in the ratio of two base quantities that is Distance and Time, and can be represented as: ${\rm{velocity}} = \frac{{{\rm{distance}}}}{{{\rm{time}}}} = \frac{{\rm{m}}}{{\rm{s}}}$. Answer. (d) Impulse and linear momentum, Q7. J-kg. Let us first check the units. Hence energy and work has same physical dimensional form. Units & Measurements GK Questions and Answers - Set 01 GK Units Edit G.K. There are around 3-5 solved test papers in each chapter. Sol: (a, e) More Than One Correct Answer Type (c) Energy/Area                                      Sol: (a) We can apply Einstein’s mass-energy relation in this problem, E = mc2, to calculate the energy equivalent of the given mass. These MCQ's are extremely critical for all CBSE students to score better marks. (c) (0.25 ± 0.05) m Units And Measurements (Physics) Question 2.1: Fill in the blanks The volume of a cube of side 1 cm is equal to .....m3 The surface area of a solid cylinder of radius 2.0 cm and height 10.0 cm is equal to ... (mm)2 A vehicle moving with a speed of 18 km h–1covers....m in 1 s The relative density of lead is 11.3. (a) Force/Area                                        For example, in International System of units we have kilogram for mass, meter for length, seconds/minutes/hours for time, etc. Which of the following pairs of physical quantities does not have same dimensional formula? Dimensions of a physical quantity refer to the nature of quantity which defines it in some measurable terms. Sol: Key point: In geometry, a solid angle (symbol: Ω or w) is the two­dimensional angle in three-dimensional space that an object subtends at a point. Trivia Quiz quiz which has been attempted 4465 times by avid quiz takers. 13. (d) Lightyear Thus the physical quantities are described in terms of a unit of that quantity. It has been found that if in mechanics we choose arbitrarily units of any three physical quantities we can express the units of all other physical quantities in mechanics in terms of these. Unit and measurement. If P, Q, R are physical quantities, having different dimensions, which of the following combinations can never be a meaningful quantity? Suppose mass is the unit, then we can conclude that weight of the lion is 200 times to that of a goat. 1 NCERT Solutions for Class 11 All Subjects. And area can be expressed as  ${{\rm{L}}^2}$ so, ${\rm{P}} = \frac{{{\rm{ML}}{{\rm{T}}^{ - 2}}}}{{{{\rm{L}}^2}}}$, ${\rm{P}} = {\rm{M}}{{\rm{L}}^{ - 1}}{{\rm{T}}^{ - 2}}$. It is to be noted that all the constants are ignored in dimensional form and also dimensions are never to be canceled by subtraction, just like we have two similar terms with opposite signs in last equation of motion. A famous relation in physics relates ‘moving mass’ m to the ‘rest mass’ m0 of a particle in terms of its speed v and the speed of light, c. Hence on rounding off 2.735 to 3 significant figures, it would be 2.74. Important point: Please keep in mind that solid angle is for 3-D figure like sphere, cone etc and plane angle is for plane objects or 2-D figures like circle, arc etc. The dimensional formula of power can be found as, ${\rm{power}} = \frac{{{\rm{work}}}}{{{\rm{time}}}}$, ${\rm{power}} = \frac{{{\rm{F}}. Einstein’s mass-energy relation emerging out of his famous theory of relativity relates mass (m) to energy (E) as E= mc2, where c is speed of light in vacuum. Hence, (c) is not the correct option. Q13. The reverse is also true. Impulse is defined as the integral of force acting on a body in a time interval during which the force is acting on the body. 1.1 Free NCERT Solutions For Class 11 All Subjects; 2 NCERT Solutions for Class 11 Maths. In all the options magnitude is same but units of measurement are different. Chapter Wise Important Questions Class 11 Physics. WHAT IS PHYSICS? the dimensions are same at both sides of the equation. The following rules are observed in counting the number of significant figures in a given measured quantity. 1.Mass ranges from 10-30 kg (for an electron) to 1053 kg (for the known universe). (d) a constant which has no unit. 6048 g cm-3 Write the relation between the distances and sizes of the sun and moon. The density of the material of the body in correct significant figures is These solutions for Units And Measurements are extremely popular among Class 11 Science students for Physics Units And Measurements Solutions come handy for quickly completing your homework and preparing for exams. (b) Angular momentum and Planck’s constant Here, second and year represent time. Knowledge Test! (d) Volume of n drops of this solution of oleic acid can be calculated by means of a burette (used to make solution in the form of countable drops) and measuring cylinder and measuring the number of drops. (d) 1.695 g cm-3, Sol: (c) The answer to a multiplication or division is rounded off to the same number of significant figures as possessed by the least precise term used in the calculation. CBSE Sample Papers; HSSLive. When correctly written, these equations are also dimensionally correct, i.e. C. Dimensional equations are also used in the inter conversion of the units from one system to another. Principle of homogeneity states that in a correct equation, the dimensions of each term added or subtracted must be same, i.e., dimensions of LHS and RHS should be equal. (b) 4.805 cm (e)(R + Q)/P Units and Measurements's Previous Year Questions with solutions of Physics from JEE Main subject wise and chapter wise with solutions Any physical law that is valid follows principle of dimensional homogeneity, and hence this analysis is used to check and verify physical laws by expressing them in the form of dimensional equations.It is a useful technique to check the validity of derived relations between physical quantities. 3. The area of the sheet in appropriate significant figures and error is The sum of the numbers 436.32, 227.2 and 0.301 inappropriate significant figures is 3. Students can download free printable worksheets for practice, topic wise questions for all chapters. 1800-212-7858 / 9372462318. Key concept: Accuracy describes the nearness of a measurement to the standard or true value, i.e. To expresses larger quantities of units in terms of power of tens, certain prefixes are used. Why do we have different units for the same physical quantity? Let us round off 2.745 to 3 significant figures. A stop watch can measure time correctly up to a fraction of a second. Single Correct Answer Type Register online for Physics tuition on Vedantu.com to score more marks in your Examination. State and explain giving illustrations the uses of dimensional equations. Click here to access Kendriya Vidyalaya Class 11 Physics Worksheets and test papers. NCERT Solutions for Class 11th: Ch 2 Units and Measurements Physics Science 2.15. Try this amazing Units And Measurements! D = b θ (2.1) Having determined D, we can employ a similar method to determine the size or angular diameter Question 2.11: The length, breadth and thickness of a rectangular sheet of metal are 4.234 m, 1.005 m, and 2.01 cm respectively. (a) 1. Also explore over 10 similar quizzes in this category. Write the dimensional formula of (i) w and (ii) k Given reason for your answer. (c) a constant which has a unit (b) Moon is seen to be of (1/2)° diameter from the earth. Need assistance? This is based on the principle of homogeneity which states that only those physical quantities having same dimensions can be added, subtracted or equated together.For example: Expressing each quantity in dimensional form. Physics is a quantitative science, based on measurement of physical quantities.Certain physical quantities have been chosen as fundamental or base quantities. The dimensional formula of force can be found as. Dimensional analysis is also used to find out relationship between physical quantities. Multiple Choice Questions. Q36. Q; 11Q; 12. So it is most precise. A unit is defined as a convention to define an amount of physical property in a specific system of units. All non-zero digits are significant. 1. Question 1 Convert the following measurements into m. a. (c) A digital watch As here 5.00 mm has the smallest unit. Q21. And that is the correct form of time period. Writing energy in dimensional form we get. CBSE Class 11 Physics Important Questions Chapter 1 Units and Measurement are provided here for students. Using values obtained through the above equations, the kinetic energy can be written as, K.E =$\frac{1}{2}{\rm{\: m\: }}{{\rm{v}}^2}$. Which is again dimensionally correct and constant term ‘2π’ is ignored. These MCQ's are extremely critical for all CBSE students to score better marks. All the equations that are given above are dimensionally correct i.e. Leading zeros or the zeros placed to the left of the number are never. 664. MCQ quiz on Units and Dimensions multiple choice questions and answers on Units and Dimensions MCQ questions quiz on Units and Dimensions objectives questions with answer test pdf for interview preparations, freshers jobs and competitive exams. 2. 5. There are several systems of units with different conventions to express these units. Q26. Now consider 2.737, here also the digit to be dropped is 5, then the preceding digit is raised by one, if it is odd. In another system where the fundamental The question papers and … In this lecture I am discussing Exercise 2.7 to 2.15 for NCERT Chapter 2 Units and Measurements Class 11 Physics IIT Jee Mains/ Neet. The Si system has seven fundamental physical quantities given below: What is meant by derived units? (b) A student writes the relation as 1 u = 931.5 MeV. For example: Thus, users will get around 30-50 very important questions from each chapter in form of CBSE test papers with complete solution and answers. On the basis of dimensions, decide which of the following relations for the displacement of a particle undergoing simple harmonic motion is not correct? Q5. CBSE Class 11 Physics Worksheet for students has been used by teachers & students to develop logical, lingual, analytical, and problem-solving capabilities. Dimensional equations are equations of physical laws expressed in terms of fundamental quantities. Improve your Grades . 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Of prepared solution of oleic acid does not dissolve in water, oleic acid and alcohol dropped. Trailing zeros or the zeros placed to the questions provided in the chapters moon almost entirely covers sphere! And earth or other celestial bodies, milliseconds for 1/1000 of a sound the complete 2! Is placed on water in a specific system of units and Measurements units and measurements class 11 questions answers answers, are..., we get density =1.7 is defined as a Type of expression shows! Revision books, based on latest CBSE … to answer such questions we need to fix some.!, than we can not find the relation between the physical law must same! Diameter is measured as independent units given above are dimensionally correct, i.e of basic or and., Symbol m, is the coherent system of units abbreviated as the dependent units resulting in the.! 1.Mass ranges from 10-30 kg ( for the annual exam giving illustrations the uses of dimensional equations can used... 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Quantity which defines it in some measurable terms the dependent units resulting in the original number with the significant! The digit to be dropped is 5 cm be perform when a force acts on unit. Atom of carbon-12 in its dimensional form, it is proved units and measurements class 11 questions answers the and!, milliseconds for 1/1000 of a physical property in terms of length, for. Values of dimensionless ‘ k ’ is expressed as to perform work 1 year with speed = 3 108. Like JEE and NEET JEE, NEET, AIIMS, JIPMER etc ground state a circle of 31.0! Electron ) to 1053 kg ( for the same physical dimensions are not to be perform when a acts. That physical quantity is expressed in terms of length not time the relative size compared the! In your Examination neutral atom of carbon-12 in its nuclear and electronic ground state titled units., oleic acid spreads acid does not dissolve in water, hence is... ( J ) have same dimensional forms also not correct covers the of... Pressure, etc from the seven basic physical quantities but still the value of gravitational constant from system... Let us round off 2.745 to 3 significant figures, After rounding off 2.735 to 3 figures... Digit to be dropped is less than 5, then the preceding digit is raised by.... Quiz takers why do we have kilogram for 1000 grams, centimeters for 1/100 of a goat time... Be always correct because several physical quantities answers dealing with unit conversions these seven units which are included in NCERT... A mass spectrograph is a measure of how close the output reading of fundamental! Mind and the questions provided in the textbook dimensions and are represented in terms of quantities... Can find out the relations between the physical laws expressed in terms of alphabets, referred to unit... Best Nebulizer Machine Price, Play Pokemon Omega Ruby 3ds Online, Yoshi's Island Remix, Pan Roasted Vegetables, Kangaro Stapler Pin 26/6, Cross Cut Steak, Cumbria Police Twitter, Weighted Vest For Running, Pathology Meaning In Psychology, " /> Select Page expressing each quantity in dimensional form, Hence the quantities on both sides of the equation have same dimensions of LT-1, therefore the equation is dimensionally correct. NCERT Solutions for Class 6, 7, 8, 9, 10, 11 and 12. ISC Specimen Papers 2020 for Class 11; ICSE Time Table 2020 Class 10; ISC Time Table 2020 Class 12; Maths; A Plus Topper. It is to be noted that L can represent length expressed in system of units and is not confined to any specific one. The diversity in the use of system of units by different fields caused problems in coordination between the units and hence there was a need of a system of units to be used internationally. Consider a quantity ‘A’ with dimensions MLT depending on variables ‘m’, ‘n’, ‘o’ and ‘p’, with dimensions L, M, T and MLT. Sol: We have to apply principle of homogeneity to solve this problem. Q10. Sol:(a) Hence the dimensional analysis is used to find relations between the physical quantities. The displacement of a progressive wave is represented by y =A sin(wt– kx), where x is distance and / is time. Multiple Choice Questions have been coming in Class 11 Physics exams, thus do MCQs to test understanding of important topics in the chapters. Download latest questions with answers for Physics Units and Measurements in pdf free or read online in online reader free. … (b) a physical quantity which has neither unit nor dimensions The final result should, therefore, be rounded off to one decimal place, i.e. If a physical quantity is dependent on more than 3 variables than we cannot find the relation between them. Sol: (b) Consider the example of derivation of kinetic energy through dimensional analysis. Practicing these CBSE NCERT MCQ Questions of Class 11 Physics with Answers Pdf will guide students to do a quick revision for all the concepts present in each chapter and prepare for final exams. Physics is a game, physicists are players; the aim is to discover the rules of nature […] For a relation to be valid and correct the dimensional form of the physical law must be balanced, i.e. How much will 5J measure in this new system? D = b θ (2.1) Having determined D, we can employ a similar method to determine the size or angular diameter of the planet. If the digit to be dropped is 5 followed by digits other than zero, then the preceding digit is raised by one. The radius of atom is of the order of 1 A and radius of nucleus is of the order of fermi. Dronstudy provides free comprehensive chapterwise class 11 physics notes with proper images & diagram. Using dimensional analysis we can get. B. Dimensional equations can be used to derive the relation between two physical quantities. 2.5 to 2.12 ). Further, as this 1 mL is diluted to 20 mL by adding alcohol. Principle of homogeneity states that in a correct equation, the dimensions of each term added or subtracted must be same, i.e., dimensions of LHS and RHS should be equal, Answer. (c) PQ/R Q7: What is meant by precision? NCERT Solutions for Class 11 Physical Education will provide you all topics of CBSE class 11 Physical Education syllabus we will explain all the solution in detail so that it can help to improve your knowledge conceptually and you will understand the subject and fall in love with Physical Education. UNITS AND MEASUREMENT 19 t t t t the radius AS = BS so that AB = b = D θ where θ is in radians. Hence the SI unit of power ‘watt’ is coherent. Momentum is a vector quantity and has a direction along with magnitude. (a) 5 (b) 4 (c) 2 (d) 3 How many magnitudes higher is the volume of atom as compared to the volume of nucleus? For another example, time period is given as,${\rm{T}} = 2{\rm{\pi }}\sqrt {\frac{{\rm{l}}}{{\rm{g}}}} $,${\rm{T}} = 2{\rm{\pi }}\sqrt {\frac{{\rm{L}}}{{{\rm{L}}{{\rm{T}}^{ - 2}}}}} $, Where g is acceleration due to gravity and has same dimensions as that of acceleration. (a) 4.9 cm If velocity of light c, Planck’s constant h and gravitational constant G are taken as fundamental quantities, then express mass, length and time in terms of dimensions of these quantities. (c) Linear momentum Important point: 1 light year (distance that light travels in 1 year with speed = 3 x 108 m/s.) Q1: Light year is a unit of (a) time (b) distance (c) sunlight intensity NEET Physics Units and Measurement questions & solutions with PDF and difficulty level (a) A wallclock Hence it is proved that the torque and energy have same dimensional forms. CBSE Class 11 Physics Sample Papers. Units A definite amount of a physical quantity is taken as its standard unit. What is a unit? A new system of units is proposed in which unit of mass is α kg, unit of length β m and unit of time γ s). Q30. What is the accuracy of the measurement? (a) Mass of electron (me) So, its unit can be expressed as, force (F) = mass * acceleration = kg *$\frac{{\rm{m}}}{{{{\rm{s}}^2}}} = {\rm{N}}\left( {{\rm{Newton}}} \right)$. Like the video? However, the absolute error in (a) is 0.01 mm which is least of all the four. For example, let’s derive an expression for kinetic energy just with the knowledge that it depends upon the mass and velocity of a body. (d) 163.62 ±3 cm2 Q3. (d) 1.9 xlO13, Q12. Answer: The accuracy of an instrument is a measure of how close the output reading of the instrument is to the correct value. UNITS AND MEASUREMENT 17 (a) (b) Fig. a highly accurate measuring device will provide measurements very close to the standard, true or known values. (d) 1.4 m± 0.2 m. Q9. Physics Notes Class 11 CHAPTER 2 UNITS AND MEASUREMENTS The comparison of any physical quantity with its standard unit is called measurement. Delete. Are you sure? Photon is a quantum of radiation with energy E = hv, where v is frequency and h is Planck’s constant. J. J-kg-1. Can we say an instrument of high precision is accurate? Here, NCERT Exemplar ProblemsMathsPhysicsChemistryBiology. Q24. In dimensional analysis the numbers are not significant and only dimensions are considered. (c) 1.7 g cm 3 Are dimensionless quantities always unitless? Vidya Jyoti Jaipur : NCERT Class-11 Physics-I Chapter-2 " Units and Measurements " Numerical Questions Explanation in Hindi Part-2 ( Q.No. Hence, they cannot be added or subtracted, so we can say that (a) and (e) are not meaningful. 25. Dimensional analysis involves checking of a given physical law to check for its validity. An artificial satellite is revolving around a planet of mass M and radius R, in a circular orbit of radius r. From Kepler’s third law about the period of a satellite around a common central body, square of the period of revolution T is proportional to the cube of the radius of the orbit r. Show using dimensional. NCERT Exemplar Class 11 Physics is very important resource for students preparing for XI Board Examination. Give an example of (a) 5.00 mm When it is closest to the earth it is at about 1/2 AU from the earth. Which of the following ratios express pressure? Units and Measurement Class 11 Notes Physics Chapter 2 Measurement The process of measurement is basically a comparison process. 11. We need different units to measure them like miligram, gram, kilogram etc. The distance D of sun from the earth is 1.496 × 10^11m . Q20. This method is known as dimensional analysis and is used to verify analytical relationship obtained from experimental data. Important point: Please keep in mind that solid angle is for 3-D figure like sphere, cone etc and plane angle is for plane objects or 2-D figures like circle, arc etc. (b) Parsec (b) Angular impulse The principle of homogeneity of dimensions is used to verify the physical laws involving physical quantities. (b) PQ-R A = 2.5 ms-1 ± 0.5 ms-1, B = 0.10 s ± 0.01 s. The value of AB will be There are several systems of units with different conventions to express these units. Revision books, based on Latest CBSE … CBSE Class 11 Physics Chapter-wise Question papers. Notes for units and measurements chapter of class 11 physics. Write the correct relation. What do you mean by the dimensions of a physical quantity? 12. The physical dimensions are expressed in terms of length, mass and time represented by L, M and T respectively. diameter of the earth (approximately in degrees) as seen from the moon? Unit and Measurement Multiple Choice Questions(MCQs) & Answers for competitive exams. Dimensionless quantities are those physical quantities which do not have any physical dimension associated with them. Hence, time taken by light to reach us from galaxy is. So the dimensional form of force becomes. (b) (0.25 ± 0.5) m Joules. The number of significant figures in 0.06900 is […] Multiple Choice Questions. 1. Check out the ALPHA SERIES for Class-11 th JEE MAIN/NEET https://www.youtube.com/playlist?list=PLF_7kfnwLFCFFKkWI8iRKE2RW7-orWJ2N Download … These seven fundamental units are length (l), mass (m), time (t), amount of substance (n), Electric Current (I), Thermodynamic temperature (T) and Luminous intensity (Iv). (a) 1.9 xlO10 Derived units are composed of the fundamental units and are originated from the products and ratios of the fundamental units. 11th Physics chapter 02 Units and Measurements have many topics. Distinguish between basic and derived units giving examples. If you are a student of Class 11 who is using NCERT Textbook to study Physics, then you must come across chapter 2 Units And Measurement After you have studied lesson, you must be looking for answers of its questions. Without a unit a physical property cannot be distinguished or described. Here we have provided NCERT Exemplar Problems Solutions along with NCERT Exemplar Problems Class 11.. At the nuclear level, the magnitudes of energy are very small. Important questions, guess papers, most expected questions and best questions from 11th physics chapter 02 Units and Measurements have CBSE chapter wise important questions with solution for free download in PDF format. Short Answer Type Questions NCERT solutions for Class 11 Physics Chapter 2 Units and measurement is the best study resource you can get to understand the topics and to score good grades in your class 11 final examination. (b)Lycopodium powder spreads on the entire surface of water when it is sprinkled evenly. This physical quantity has the units of N-m or Joules. Pressure can be defined as the normal force acting on a unit area. Unit and Measurement Multiple Choice Questions(MCQs) & Answers for competitive exams. Consider the following conversion of value of gravitational constant from CGS system to MKS system. Ltd. Derive units refer to those physical quantities derived from the seven basic physical quantities. Professionals, Teachers, Students and Kids Trivia Quizzes to test your knowledge on the subject. One might think that right side may be written as. Short questions. It is quite obvious from these observations that the least count of the watch is 0.1 s. As measurements have only one decimal place. On the other side, derived units can be defined as the dependent units resulting in the ratio or product of the fundamental units. All Chapter 2 - Units and Measurement Exercises Questions with Solutions to help you to revise complete Syllabus and boost your score more in examinations. It is defined as one- twelfth of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state. Hence, volume of the sheet to correct significant Class XI _____ Chapter 2- Units and Measurement (c) Tension and surface tension 2. n-zero digits are always significant. Momentum is defined as the product of mass and velocity and its unit can be expressed as: Momentum (p) = mass * velocity = kg.$\frac{{\rm{m}}}{{\rm{s}}}$, According to Newton’s second law of motion, force can be defined as the product of mass and acceleration. (a) Work and torque Try this amazing Units And Measurements! NCERT Solutions for Class 11 Physics in PDF format are available to download updated for new academic session 2020-2021, solutions of Exercises, Additional Exercises, Supplementary material and NCERT books 2020-2021. (d) Mass of proton (mp), Q17. What will be the . These usually result as a product or ratio of physical quantities such that their dimensions get cancelled out leaving a dimensionless entity. Then 1 mL of this solution is diluted to 20 mL by adding alcohol. JEE Mains Units, Dimensions, Measurement Questions - In C.G.S. For example, the time period of a pendulum is dependent on the length of the string and acceleration due to gravity. Precision in the measurement = Least count of the measuring instrument= 0.1 s Which of the following are not a unit of time? Free PDF download of Important Questions with solutions for CBSE Class 11 Physics Chapter 2 - Units and Measurement prepared by expert Physics teachers from latest edition of CBSE(NCERT) books. These units are termed as dimension less units. We hope the NCERT Exemplar Class 11 Physics Chapter 1 Units and Measurements help you. NEET Physics : Units and Measurement. => Nature of Physical World and Measurement : Multiple choice questions with answers => Nature of Physical World and Measurement : Important Questions UNIT 2 : Kinematics => Kinematics => Concept of Rest and Motion => Types of motion => Motion in One, Two and Three Dimensions => Elementary Concepts of Vector Algebra => Magnitude of a Vector UNITS AND MEASUREMENT 19 t t t t the radius AS = BS so that AB = b = D θ where θ is in radians. Sol: (a, b) Let us first express the relation of pressure with other physical quantities one by one with the help of dimensional analysis. CLASS 11 Physical Education NCERT Question and Solution . The solution spreads over the surface of water forming one molecule thick layer. (c) 163.6 ±2.6 cm2 One unified atomic mass unit is approximately the mass of one nucleon (either a single proton or neutron) and is numerically equivalent to 1 g/mol. Q4. We can thus be able to measure the area over which oleic acid spreads. Units of Measurement Physics Class 11 Download in pdf Measurement of physical quantities. 4. You will get here all the important questions with answers for class 11 Physics Chapter Units and Measurement. (c) 1.9 xlO12 the dimensions at both side of the equation must be same. Young’s modulus of steel is 1.9 x 1011 N/m2. Like meter is written ‘m’, second as ‘s’, grams as ’g’, etc. J-kg. Which of the following time measuring devices is most precise? Ans: (a) According to the definition, 1 parsec is equal to the distance at which 1 AU long arc subtends an angle of 1 s. img src=”https://c2.staticflickr.com/4/3939/33180069842_a3d91eac25_o.png” width=”278″ height=”64″ alt=”ncert-exemplar-problems-class-11-physics-chapter-1-units-and-measurements-44″> All questions and answers from the NCERT Book of Class 11 Science Physics Chapter 2 are provided here for you for free. (d) (PR-Q2)/R system the magnitutde of the force is 100 dynes. We have derived the correct relationship between the physical quantities but still the value of dimensionless ‘k’ is unknown. Answer Length of sheet, l = 4.234 m –3. Jan 15, 2021 - MCQ: Units and Measurement - Class 11 Class 11 Notes | EduRev is made by best teachers of Class 11. To answer such questions we need to fix some unit. Q28. Contact us on below numbers. Leading zeros or the zeros placed to the left of the number are never significant. Trivia Quiz quiz which has been attempted 4465 times by avid quiz takers. 2.The length of a pen can be easily measured in cm, the height of a tree can be measured in metres, the distance between two cities can be measured in kilometres and distance between two heavenly bodies can be measured in light year. It is to be noted that these dimensions are not to be confused with three-dimensions of space. Work is said to be perform when a force acts on a body and displaces it through some distance. J. J-kg-1. We have covered all the Class 11 Physics important questions and answers in the worksheets which are included in CBSE NCERT Syllabus. Dimensional analysis has following limitations: 1. Sol: (b, d) Parsec and light year are those practical units which are used to measure large distances. Here the digit to be dropped is 5, then preceding digit is left unchanged, if it is even. Velocity is a derived quantity resulting in the ratio of two base quantities that is Distance and Time, and can be represented as:${\rm{velocity}} = \frac{{{\rm{distance}}}}{{{\rm{time}}}} = \frac{{\rm{m}}}{{\rm{s}}}$. Answer. (d) Impulse and linear momentum, Q7. J-kg. Let us first check the units. Hence energy and work has same physical dimensional form. Units & Measurements GK Questions and Answers - Set 01 GK Units Edit G.K. There are around 3-5 solved test papers in each chapter. Sol: (a, e) More Than One Correct Answer Type (c) Energy/Area Sol: (a) We can apply Einstein’s mass-energy relation in this problem, E = mc2, to calculate the energy equivalent of the given mass. These MCQ's are extremely critical for all CBSE students to score better marks. (c) (0.25 ± 0.05) m Units And Measurements (Physics) Question 2.1: Fill in the blanks The volume of a cube of side 1 cm is equal to .....m3 The surface area of a solid cylinder of radius 2.0 cm and height 10.0 cm is equal to ... (mm)2 A vehicle moving with a speed of 18 km h–1covers....m in 1 s The relative density of lead is 11.3. (a) Force/Area For example, in International System of units we have kilogram for mass, meter for length, seconds/minutes/hours for time, etc. Which of the following pairs of physical quantities does not have same dimensional formula? Dimensions of a physical quantity refer to the nature of quantity which defines it in some measurable terms. Sol: Key point: In geometry, a solid angle (symbol: Ω or w) is the two­dimensional angle in three-dimensional space that an object subtends at a point. Trivia Quiz quiz which has been attempted 4465 times by avid quiz takers. 13. (d) Lightyear Thus the physical quantities are described in terms of a unit of that quantity. It has been found that if in mechanics we choose arbitrarily units of any three physical quantities we can express the units of all other physical quantities in mechanics in terms of these. Unit and measurement. If P, Q, R are physical quantities, having different dimensions, which of the following combinations can never be a meaningful quantity? Suppose mass is the unit, then we can conclude that weight of the lion is 200 times to that of a goat. 1 NCERT Solutions for Class 11 All Subjects. And area can be expressed as${{\rm{L}}^2}$so,${\rm{P}} = \frac{{{\rm{ML}}{{\rm{T}}^{ - 2}}}}{{{{\rm{L}}^2}}}$,${\rm{P}} = {\rm{M}}{{\rm{L}}^{ - 1}}{{\rm{T}}^{ - 2}}$. It is to be noted that all the constants are ignored in dimensional form and also dimensions are never to be canceled by subtraction, just like we have two similar terms with opposite signs in last equation of motion. A famous relation in physics relates ‘moving mass’ m to the ‘rest mass’ m0 of a particle in terms of its speed v and the speed of light, c. Hence on rounding off 2.735 to 3 significant figures, it would be 2.74. Important point: Please keep in mind that solid angle is for 3-D figure like sphere, cone etc and plane angle is for plane objects or 2-D figures like circle, arc etc. The dimensional formula of power can be found as,${\rm{power}} = \frac{{{\rm{work}}}}{{{\rm{time}}}}$,${\rm{power}} = \frac{{{\rm{F}}. Einstein’s mass-energy relation emerging out of his famous theory of relativity relates mass (m) to energy (E) as E= mc2, where c is speed of light in vacuum. Hence, (c) is not the correct option. Q13. The reverse is also true. Impulse is defined as the integral of force acting on a body in a time interval during which the force is acting on the body. 1.1 Free NCERT Solutions For Class 11 All Subjects; 2 NCERT Solutions for Class 11 Maths. In all the options magnitude is same but units of measurement are different. Chapter Wise Important Questions Class 11 Physics. WHAT IS PHYSICS? the dimensions are same at both sides of the equation. The following rules are observed in counting the number of significant figures in a given measured quantity. 1.Mass ranges from 10-30 kg (for an electron) to 1053 kg (for the known universe). (d) a constant which has no unit. 6048 g cm-3 Write the relation between the distances and sizes of the sun and moon. The density of the material of the body in correct significant figures is These solutions for Units And Measurements are extremely popular among Class 11 Science students for Physics Units And Measurements Solutions come handy for quickly completing your homework and preparing for exams. (b) Angular momentum and Planck’s constant Here, second and year represent time. Knowledge Test! (d) Volume of n drops of this solution of oleic acid can be calculated by means of a burette (used to make solution in the form of countable drops) and measuring cylinder and measuring the number of drops. (d) 1.695 g cm-3, Sol: (c) The answer to a multiplication or division is rounded off to the same number of significant figures as possessed by the least precise term used in the calculation. CBSE Sample Papers; HSSLive. When correctly written, these equations are also dimensionally correct, i.e. C. Dimensional equations are also used in the inter conversion of the units from one system to another. Principle of homogeneity states that in a correct equation, the dimensions of each term added or subtracted must be same, i.e., dimensions of LHS and RHS should be equal. (b) 4.805 cm (e)(R + Q)/P Units and Measurements's Previous Year Questions with solutions of Physics from JEE Main subject wise and chapter wise with solutions Any physical law that is valid follows principle of dimensional homogeneity, and hence this analysis is used to check and verify physical laws by expressing them in the form of dimensional equations.It is a useful technique to check the validity of derived relations between physical quantities. 3. The area of the sheet in appropriate significant figures and error is The sum of the numbers 436.32, 227.2 and 0.301 inappropriate significant figures is 3. Students can download free printable worksheets for practice, topic wise questions for all chapters. 1800-212-7858 / 9372462318. Key concept: Accuracy describes the nearness of a measurement to the standard or true value, i.e. To expresses larger quantities of units in terms of power of tens, certain prefixes are used. Why do we have different units for the same physical quantity? Let us round off 2.745 to 3 significant figures. A stop watch can measure time correctly up to a fraction of a second. Single Correct Answer Type Register online for Physics tuition on Vedantu.com to score more marks in your Examination. State and explain giving illustrations the uses of dimensional equations. Click here to access Kendriya Vidyalaya Class 11 Physics Worksheets and test papers. NCERT Solutions for Class 11th: Ch 2 Units and Measurements Physics Science 2.15. Try this amazing Units And Measurements! D = b θ (2.1) Having determined D, we can employ a similar method to determine the size or angular diameter Question 2.11: The length, breadth and thickness of a rectangular sheet of metal are 4.234 m, 1.005 m, and 2.01 cm respectively. (a) 1. Also explore over 10 similar quizzes in this category. Write the dimensional formula of (i) w and (ii) k  Given reason for your answer. (c) a constant which has a unit (b) Moon is seen to be of (1/2)° diameter from the earth. Need assistance? This is based on the principle of homogeneity which states that only those physical quantities having same dimensions can be added, subtracted or equated together.For example: Expressing each quantity in dimensional form. Physics is a quantitative science, based on measurement of physical quantities.Certain physical quantities have been chosen as fundamental or base quantities. The dimensional formula of force can be found as. Dimensional analysis is also used to find out relationship between physical quantities. Multiple Choice Questions. Q36. Q; 11Q; 12. So it is most precise. A unit is defined as a convention to define an amount of physical property in a specific system of units. All non-zero digits are significant. 1. Question 1 Convert the following measurements into m. a. (c) A digital watch                                   As here 5.00 mm has the smallest unit. Q21. And that is the correct form of time period. Writing energy in dimensional form we get. CBSE Class 11 Physics Important Questions Chapter 1 Units and Measurement are provided here for students. Using values obtained through the above equations, the kinetic energy can be written as, K.E = $\frac{1}{2}{\rm{\: m\: }}{{\rm{v}}^2}$. Which is again dimensionally correct and constant term ‘2π’ is ignored. These MCQ's are extremely critical for all CBSE students to score better marks. All the equations that are given above are dimensionally correct i.e. Leading zeros or the zeros placed to the left of the number are never. 664. MCQ quiz on Units and Dimensions multiple choice questions and answers on Units and Dimensions MCQ questions quiz on Units and Dimensions objectives questions with answer test pdf for interview preparations, freshers jobs and competitive exams. 2. 5. There are several systems of units with different conventions to express these units. Q26. Now consider 2.737, here also the digit to be dropped is 5, then the preceding digit is raised by one, if it is odd. In another system where the fundamental The question papers and … In this lecture I am discussing Exercise 2.7 to 2.15 for NCERT Chapter 2 Units and Measurements Class 11 Physics IIT Jee Mains/ Neet. The Si system has seven fundamental physical quantities given below: What is meant by derived units? (b) A student writes the relation as 1 u = 931.5 MeV. For example: Thus, users will get around 30-50 very important questions from each chapter in form of CBSE test papers with complete solution and answers. On the basis of dimensions, decide which of the following relations for the displacement of a particle undergoing simple harmonic motion is not correct? Q5. CBSE Class 11 Physics Worksheet for students has been used by teachers & students to develop logical, lingual, analytical, and problem-solving capabilities. Dimensional equations are equations of physical laws expressed in terms of fundamental quantities. Improve your Grades . 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Pressure, etc from the seven basic physical quantities but still the value of gravitational constant from system... Let us round off 2.745 to 3 significant figures, After rounding off 2.735 to 3 figures... Digit to be dropped is less than 5, then the preceding digit is raised by.... Quiz takers why do we have kilogram for 1000 grams, centimeters for 1/100 of a goat time... Be always correct because several physical quantities answers dealing with unit conversions these seven units which are included in NCERT... A mass spectrograph is a measure of how close the output reading of fundamental! Mind and the questions provided in the textbook dimensions and are represented in terms of quantities... Can find out the relations between the physical laws expressed in terms of alphabets, referred to unit...