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Units and Measurements multiple choice questions (MCQs) are a powerful way to strengthen your understanding of concepts and prepare effectively for exams. For Class 11 Physics chapter 2 Units and Measurements, practicing MCQs is essential to master the foundational topics like SI units, significant figures, dimensional analysis, and error measurements.
These units and measurements class 11 mcq with answers not only help in revising the chapter quickly but also improve your problem-solving speed, making them an excellent tool for board exams and competitive tests like JEE and NEET. With resources like units and measurements class 11 mcq pdf download, students can access a comprehensive set of units and measurements mcq questions and answers for self-assessment.
Solving units and measurements mcq class 11 Physics ensures a clear grasp of the topic while building confidence for exams. Start practicing now and make the most of these valuable learning materials to excel in Class 11 Physics.
Class 11 Physics Units and Measurements Overview
Class 11 chapter 2 Units and Measurements is foundational for understanding physics as a precise and quantitative science. It focuses on the methods used to measure physical quantities, the systems of units, and the errors and uncertainties associated with measurements. This chapter lays the groundwork for problem-solving in physics by emphasizing the importance of accurate and reliable measurements.
Physical Quantities
- Physical quantities are measurable attributes of physical phenomena.
- These are classified as fundamental quantities (e.g., length, mass, time) and derived quantities (e.g., velocity, force, energy).
Systems of Units
- Fundamental Units: Independent units for fundamental quantities.
- Derived Units: Units derived from fundamental units.
- International System of Units (SI):
-
- Base units: meter (m), kilogram (kg), second (s), ampere (A), kelvin (K), mole (mol), and candela (cd).
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- Other systems: CGS, FPS (less commonly used).
Measurement Techniques
- Direct measurement: Using instruments like a ruler or stopwatch.
- Indirect measurement: Calculated using formulas and known quantities.
Dimensional Analysis
- The dimensions of a physical quantity are represented as powers of fundamental quantities (e.g., [M], [L], [T]).
- Applications:
-
-
- Checking dimensional consistency of equations.
- Deriving relationships between physical quantities.
-
Significant Figures
- Digits in a number that are reliable and contribute to its precision.
- Rules for identifying significant figures in measured values.
- Importance in calculations: Addition, subtraction, multiplication, and division.
Errors in Measurement
- Systematic Errors: Reproducible inaccuracies due to equipment or methodology.
- Random Errors: Variations due to unpredictable factors.
- Absolute Error: Difference between measured and true value.
- Relative Error: Ratio of absolute error to the true value.
- Percentage Error: Relative error expressed as a percentage.
Precision and Accuracy
- Precision: Degree of agreement among repeated measurements.
- Accuracy: How close a measurement is to the true value.
Uncertainty in Measurement
- Expressed using standard notation like
.
- Combined uncertainties in addition, subtraction, multiplication, and division.
Instrumental Errors
- Least count: The smallest measurable value by an instrument.
- Vernier calipers and screw gauge: Used for precise measurements.
Applications of Units and Measurements
- Establishing universal standards.
- Ensuring consistency in experiments and calculations.
Class 11 Physics Units and Measurements MCQ Questions and Answers
Question 1: The symbol to represent “Amount of Substance” is ________
- K
- A
- Cd
- mol
Answer: (d) mol
Explanation: The amount of substance is a basic physical quantity in the SI system and is measured in moles, represented by the symbol “mol”. It refers to the quantity of a substance containing the same number of entities (atoms, molecules, etc.) as there are in 12 grams of carbon-12.
Question 2: Which among the following is the Supplementary Unit?
- Mass
- Time
- Solid angle
- Luminosity
Answer: (c) Solid angle
Explanation: Supplementary units are specific units used to measure plane angles and solid angles. Solid angle, measured in steradians, is considered supplementary because it complements the base units in describing spatial dimensions.
Question 3: What is the unit of solid angle?
- Second
- Steradian
- Kilogram
- Candela
Answer: (b) Steradian
Explanation: A steradian (sr) is the SI unit used to measure solid angles in three-dimensional space. It is derived from the geometry of spheres, where one steradian is the angle subtended by an area on a sphere equal to the square of the radius.
Question 4: AU is the unit of ________
- Astronomy Unit
- Astronomical Unit
- Astrological Unit
- Archaeological Unit
Answer: (b) Astronomical Unit
Question 5: Explanation: An Astronomical Unit (AU) is a standard unit of distance used in astronomy. It is approximately equal to the average distance between the Earth and the Sun, which is about 149.6 million kilometers.
Dimensions of kinetic energy are the same as that of ________
- Acceleration
- Velocity
- Work
- Force
Answer: (c) Work
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Question 6: Explanation: The dimensions of kinetic energy and work are identical because both represent energy. Kinetic energy is the energy of motion, and work is the energy transferred when a force moves an object. Both have dimensions of
.
Farad is the unit of ________
- Luminosity
- Wavelength
- Permittivity
- Inertia
Answer: (c) Permittivity
Question 7: Explanation: The farad (F) is the SI unit of capacitance, which quantifies a system’s ability to store electric charge. Permittivity relates to how a material influences the electric field and is measured in farads per meter.
Electron volt is a unit of ________
- Luminosity
- Frequency
- Force
- Energy
Answer: (d) Energy
Explanation: An electron volt (eV) is a unit of energy commonly used in atomic and particle physics. It is defined as the amount of kinetic energy gained by an electron when it moves through a potential difference of one volt.
Question 8: Joule second is the unit of ________
- Force
- Angular momentum
- Energy
- Power
Answer: (b) Angular momentum
Explanation: The joule second (Js) is the unit of angular momentum, which measures the rotational motion of an object. It is also associated with the quantization of angular momentum in quantum mechanics.
Question 9: The smallest value which is measured using an instrument is known as ________
- Absolute count
- Least count
- Round-off value
- Minimum count
Answer: (b) Least count
Explanation: The least count of an instrument is the smallest measurement it can accurately detect. For instance, the least count of a standard ruler is typically 1 millimeter.
Question 1o: Which is the system of unit?
- SMS system
- MKP system
- FPS System
- CJS System
Answer: (c) FPS System
Explanation: The FPS system, also known as the Foot-Pound-Second system, is one of the older systems of units. In this system, length is measured in feet, weight in pounds, and time in seconds.
Get NCERT Solutions for Class 11 Physics All Chapters
- Chapter 1: Physical World
- Chapter 2: Units and Measurements
- Chapter 3: Motion in a Straight Line
- Chapter 4: Motion in a Plane
- Chapter 5: Laws of Motion
- Chapter 6: Work, Energy, and Power
- Chapter 7: System of Particles and Rotational Motion
- Chapter 8: Gravitation
- Chapter 9: Mechanical Properties of Solids
- Chapter 10: Mechanical Properties of Fluids
- Chapter 11: Thermal Properties of Matter
- Chapter 12: Thermodynamics
- Chapter 13: Kinetic Theory
- Chapter 14: Oscillations
- Chapter 15: Waves
FAQs on Units and Measurements MCQ Class 11 Physics
What are Units and Measurements in Class 11 Physics?
Units and Measurements in Class 11 Physics form the foundation for understanding and quantifying physical phenomena. This chapter covers the types of units (base and derived), methods of measuring physical quantities, dimensional analysis, and error analysis. Mastery of these concepts helps in solving problems accurately in physics and other scientific disciplines.
Why are MCQs important for Units and Measurements in Class 11 Physics?
MCQs are crucial for testing your understanding of Units and Measurements. They focus on conceptual clarity, application of dimensional analysis, and accuracy in solving problems. Practicing these questions not only prepares you for school exams but also strengthens your foundation for competitive exams like JEE and NEET.
How can I prepare for Units and Measurements MCQ questions effectively?
To prepare effectively, start by understanding the theory and formulas in the chapter. Next, solve a variety of MCQs from reliable sources to test your grasp of the concepts. Pay attention to mistakes and revise key topics like significant figures, types of errors, and dimensional formulas. Solving MCQs regularly improves speed and accuracy.
Where can I find Units and Measurements Class 11 MCQ questions with answers?
You can find a comprehensive collection of Units and Measurements MCQ questions with answers in dedicated study materials, online PDFs, and educational websites. These resources often include detailed solutions, making it easier to understand and learn from your mistakes.