Significant figures are used to demonstrate the number which is presented in the form of digits. These digits represent numbers in a meaningful way. Instead of figures, the phrase significant digits is frequently used. By counting all the values starting with the first non-zero digit on the left, we may determine the number of significant digits. The number 13.75, for example, includes four significant digits.

Any non-zero numbers or trapped zeros are significant figures. Leading and trailing zeros are not included.

Definition: Significant figures are the digits of a number that have meaning for the measurement’s resolution in physics. In physics, they are also known as significant figures.

Significant Figures Physics Questions with Solutions

Q1: What are Significant Figures?

Answer:

In Physics, Significant figures are the digits of a number that have meaning for the measurement’s resolution. It is the number of digits used to express a quantity that has been measured or calculated.

We may illustrate how exact a number is by using significant figures. We risk the integrity of what this number represents by expressing it outside the location where we have actually measured (and hence are certain of). It is critical to employ major figures correctly throughout our scientific careers after studying and understanding them.

Q2: Give examples of Significant Figures.

Answer:

Significant Figures examples are as follows:

• 4308 – 4 significant figures
• 40.05 – 4 significant figures
• 470,000 – 2 significant figures
• 4.00 – 3 significant figures
• 0.00500 – 3 significant figures

Q3: Give the number of significant figures in each measurement.

1. 36.7 m
2. 0.006606 s
3. 2,002 kg
4. 306,490,000 people

Answer:

1. This measurement has three significant numbers since all nonzero digits are significant.
2. The first three zeros are insignificant, but the zero between the sixes is, hence this number has four significant figures.
3. This measurement includes four significant figures because the two zeros between the two are significant.
4. The four trailing zeros in the number aren’t significant, but the other five are, making this a five-figure number.

Q4: Express the final answer to the proper number of significant figures.

1. 101.2 + 18.702 = ?
2. 202.88 − 1.013 = ?

Answer:

1. If we add these two figures together with a calculator, we get 119.902. However, because most calculators do not recognise significant figures, we’ll have to round up to tenths place. As a result, we eliminate the 02 and give a final score of 119.9. (rounding off).
2. A calculator would come up with the number 201.867. We must, however, limit our final response to the hundredths place. We round up and return a final answer of 201.87 because the first number dropped is 7, which is greater than 5.

Q5: Calculate the correct number of significant figures for the final solution:

1. 76.4 × 180.4 = ?
2. 934.9 ÷ 0.00455 = ?

Answer:

1. There are three significant figures in the first number, and four significant figures in the second. As a result, we only use three significant figures in our final answer: 76.4 180.4 = 13,782.56 = 13,800.
2. The first number has four significant figures, whereas the second number only has three. As a result, we chose to keep our final answer to three major figures: 934.9 ÷ 0.00455 = 205,472.5275… = 205,000.

Q6: Exercises of rounding to the correct number of significant figures with a 5 as the first non-significant figure:

1. Round 4.7475 to 4 significant figures
2. Round 4.7465 to 4 significant figures

Answer:

1. Because the first non-significant digit is 5, and we round the last significant figure up to 6 to make it even, 4.7475 becomes 4.748.
2. Because the first non-significant figure is 5, and the last significant figure is even, 4.7465 becomes 4.746.

Q7: How many significant figures are in the measurement 0.0082 L?

Answer:

There are five digits in the number provided in the question: three zero digits and two nonzero digits. Two of the zero digits appear after the decimal, while one appears before the decimal. Regardless, because there are no nonzero digits between the three zero digits, they are not regarded as significant figures. As a result, only the first two nonzero numbers are significant. As a result, there are only two significant figures in this measurement, 82.

Q8: How many significant figures should the answer to this calculation contain?

\(\begin{array}{l}\frac{1.014 + 0.07}{5.11}\end{array} \)

1. 2
2. 3
3. 4
4. 1

Answer: d) 1

Explanation: The term in the equation with the fewest significant figures will ultimately decide the number of significant figures in the final result. Let’s look at the parts of the expression we’ve been given.

1.014 → 4 significant figures

0.07 → 1 significant figure

5.11 → 3 significant figures

Because the expression’s least precise term includes only one significant figure, our final answer will also have only one.

Q9: How many significant figures are in the number 0.00150?

1. 5
2. 3
3. 6
4. 2

Answer: b) 3

Explanation: It’s important to remember that all leading zeros aren’t significant.

As a result, we begin calculating significant figures where the 1 is for 0.00150. Because it is a trailing zero discovered after the decimal point, the last 0 is significant. Thus, there are 3 significant figures in the given number.

Q10: Calculate and give the answer using the correct number of significant figures: 1.02 + 8.2 + 3.33 + 9.781

1. 22.3
2. 22.33
3. 22.331
4. 22

Answer: a) 22.3

Explanation: To begin, add up the numbers.

1.02 + 8.2 + 3.33 + 9.781 = 22.331

Because this is an addition, the outcome must have the same number of decimal places as the value with the fewest decimal places. Because 8.2 has the smallest number of decimal places, the solution must only contain one digit after the decimal point.

Q11: Calculate and give the answer using the correct number of significant figures.

\(\begin{array}{l}\frac{(3.4 + 100.33)}{(2.5 – 0.11)}\end{array} \)

1. 43
2. 40
3. 43.4
4. 43.40

Answer: a) 43

Explanation: Keep track of the number of significant figures at the conclusion of each step in multistep calculations so we know how many significant figures to round to at the end of the entire calculation. Round intermediate steps to ensure precision. In the parenthesis, do the addition and subtraction first.

3.4+ 100.33 = 103.73

Remember that the result for addition must have the same number of digits after the decimal point as the number in the question with the fewest decimal points. The result of our addition should only have four significant figures. The last significant digit will be underlined to remind us that the solution should only have four significant figures: 103.73

Next, do the subtraction.

2.5 − 0.11 = 2.39

Because the rules for significant numbers in addition and subtraction are the same, we only need two significant figures in our answer. This step’s last significant figure will be underlined as well: 2.39

Now, divide these two numbers:

\(\begin{array}{l}\frac{103.73}{2.39}\end{array} \)

= 43.40167364

This is when the importance of underlining significant digits in the previous steps comes into play. Remember that the result of multiplication and division has the same number of significant figures as the factor with the smallest number.

To reflect the least amount of significant figures found in the division, round the final answer to 2 significant figures. As a result, 43.40167364 equals 43.

Q12: Calculate and provide the correct number of significant figures.

\(\begin{array}{l}\frac{566.11 \cdot 12.333}{3.45}\end{array} \)

1. 2023
2. 2000
3. 2020
4. 2023.7

Answer: c) 2020

Explanation: First, complete the calculation.

\(\begin{array}{l}\frac{566.11 \cdot 12.333}{3.45}\end{array} \)

= 2023.720183

Remember that the solution for multiplication and division utilises the least number of significant numbers in the question. 3.45 has the least number of significant figures (3 in this case). After that, the final answer should be rounded up to only three significant figures. 2023.720183 rounded to three significant figures is 2020.

Q13: Calculate and give the answer with the correct number of significant figures.

(0.05 + 0.123) x (1.02 + 0.9)

1. 0.3321
2. 0.332
3. 0.3
4. 0.33

Answer: d) 0.33

Explanation: Keep track of the number of significant figures at the end of each step in multistep calculations so we know how many significant figures to round to at the end of the entire calculation. To maintain accuracy, you must round intermediate steps.

Begin by solving the two addition problems in the parenthesis.

0.05 + 0.123 = 0.173

Remember that the result for addition must have the same number of digits after the decimal point as the number in the question with the fewest decimal points. The result of our addition should only have two significant figures. The last significant digit will be underlined to remind you that the solution should only have two significant figures: 0.173

1.02 + 0.9 = 1.92

Using the same logic as before, perform the second addition. The last significant number will be underlined to remind you that the solution should only have two significant figures: 1.92

Now, multiply:

0.173 × 1.92 = 0.33216

Because both factors have two significant figures, we should only have two significant figures in our final answer. The fraction 0.33216 is rounded to 0.33.

Q14: State the number of significant figures in the following:

1. 0.007 m²
2. 2.64×10²⁴ kg
3. 0.2370 g.cm^-3
4. 6.320J
5. 6.032 Nm^-2
6. 0.0006032 m²

Answer:

1. 0.007 = 7 x 10^-3. Significant digit = 7. Thus, only one significant digit.
2. Number of significant figures = 3
3. Numbers that are not zero are always significant. Before a non-zero number, all zeros are insignificant. Significant are all zeroes to the right of the decimal point and at the end of the number.

The zero before the decimal point is the only non-significant digit here. As a result, the number of significant digits is four.

1. Numbers that are not zero are always significant. Significant are all zeroes to the right of the decimal point and at the end of the number. As a result, the number of significant digits is 4.
2. All of the digits are significant. (there is no leading zero or trailing zero)

The number of significant digits is equal to 4.

1. Significant digits = 6032

No. of significant digits = 4

Q15: Briefly describe Significant Figures Rules.

Answer:

When measuring the significant figures of a determined measurement, certain rules must be followed.

The following are the fundamentals of the law:

• All non-zero digits are important.
• Zeroes between non-zero digits are important.
• Only the last zero or the trailing zero in the decimal section are significant.

The following are the significant figures rules governing significant figure determination:

• The non-zero digits are the ones that count.
• For example, there are four significant digits in 6575 cm and three significant figures in 0.543.
• If there is a zero before the non-zero digit, it is not relevant. The position of the decimal point is indicated by the previous zero; there is only one figure in 0.005 and three in 0.00232.
• It’s also a significant figure if there’s a zero between two non-zero digits.
• 4.5006 has five major figures, for example.
• A number with zeroes at the end or on the right side is also significant.
• 0.500, for instance, contains three significant digits.
• Because these are inexact numbers, counting the number of objects, such as 5 bananas and 10 oranges, yields endless figures.

Practise Questions on Significant Figures

Q1: What is the purpose of Significant Figures?

Q2: How many Significant figures in each term?

1. 34.6209
2. 0.003048
3. 5010.0
4. 4032.090

Q3: How many significant figures in each term?

1. 1.40 x 10³
2. 6.01
3. 02947.1
4. 583.02

Q4: Calculate and give the answer using the correct number of significant figures.

1.2 + 3 + 9.65 + 10.881

1. 25
2. 24.7
3. 24.73
4. 24

Q5: How many significant figures are in the number 0.50210?

1. 2
2. 4
3. 3
4. 5

Neeraj Anand, Param Anand

Er. Neeraj K.Anand is a freelance mentor and writer who specializes in Engineering & Science subjects. Neeraj Anand received a B.Tech degree in Electronics and Communication Engineering from N.I.T Warangal & M.Tech Post Graduation from IETE, New Delhi. He has over 30 years of teaching experience and serves as the Head of Department of ANAND CLASSES. He concentrated all his energy and experiences in academics and subsequently grew up as one of the best mentors in the country for students aspiring for success in competitive examinations. In parallel, he started a Technical Publication "ANAND TECHNICAL PUBLISHERS" in 2002 and Educational Newspaper "NATIONAL EDUCATION NEWS" in 2014 at Jalandhar. Now he is a Director of leading publication "ANAND TECHNICAL PUBLISHERS", "ANAND CLASSES" and "NATIONAL EDUCATION NEWS". He has published more than hundred books in the field of Physics, Mathematics, Computers and Information Technology. Besides this he has written many books to help students prepare for IIT-JEE and AIPMT entrance exams. He is an executive member of the IEEE (Institute of Electrical & Electronics Engineers. USA) and honorary member of many Indian scientific societies such as Institution of Electronics & Telecommunication Engineers, Aeronautical Society of India, Bioinformatics Institute of India, Institution of Engineers. He has got award from American Biographical Institute Board of International Research in the year 2005.

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CBSE Unit-wise Class 11 Physics Syllabus

Below we have provided the details of the CBSE Physics topics under each unit as per the revised CBSE Class 11 Physics Syllabus for the 2023-24 academic year. Go through it to get the details of the chapters given below.

Unit-I: Physical World and Measurement

Chapter 2: Units and Measurements

Need for measurement: Units of measurement; systems of units; SI units, fundamental and derived units. Length, mass and time measurements; accuracy and precision of measuring instruments; errors in measurement; significant figures.

Dimensions of physical quantities, dimensional analysis and its applications.

Unit-II: Kinematics

Chapter 3: Motion in a Straight Line

Frame of reference, Motion in a straight line, Elementary concepts of differentiation and integration for describing motion, uniform and nonuniform motion, and instantaneous velocity, uniformly accelerated motion, velocity-time and position-time graphs. Relations for uniformly accelerated motion (graphical treatment).

Chapter 4: Motion in a Plane

Scalar and vector quantities; position and displacement vectors, general vectors and their notations; equality of vectors, multiplication of vectors by a real number; addition and subtraction of vectors, relative velocity, Unit vector; resolution of a vector in a plane, rectangular components, Scalar and Vector product of vectors.

Motion in a plane, cases of uniform velocity and uniform acceleration-projectile motion, uniform circular motion.

Unit-III: Laws of Motion

Chapter 5: Laws of Motion

Intuitive concept of force, Inertia, Newton’s first law of motion; momentum and Newton’s second law of motion; impulse; Newton’s third law of motion (recapitulation only). Law of conservation of linear momentum and its applications. Equilibrium of concurrent forces, Static and kinetic friction, laws of friction, rolling friction, lubrication.

Dynamics of uniform circular motion: Centripetal force, examples of circular motion (vehicle on a level circular road, vehicle on a banked road).

Unit-IV: Work, Energy and Power

Chapter 6: Work, Energy and Power

Work done by a constant force and a variable force; kinetic energy, work-energy theorem, power.

Notion of potential energy, potential energy of a spring, conservative forces: conservation of mechanical energy (kinetic and potential energies); non-conservative forces: motion in a vertical circle; elastic and inelastic collisions in one and two dimensions.

Unit-V: Motion of System of Particles and Rigid Body

Chapter 7: System of Particles and Rotational Motion

Centre of mass of a two-particle system, momentum conservation and centre of mass motion. Centre of mass of a rigid body; centre of mass of a uniform rod. Moment of a force, torque, angular momentum, law of conservation of angular momentum and its applications.

Equilibrium of rigid bodies, rigid body rotation and equations of rotational motion, comparison of linear and rotational motions.

Moment of inertia, radius of gyration, values of moments of inertia for simple geometrical objects (no derivation).

Unit-VI: Gravitation

Chapter 8: Gravitation

Kepler’s laws of planetary motion, universal law of gravitation. Acceleration due to gravity and its variation with altitude and depth. Gravitational potential energy and gravitational potential, escape speed, orbital velocity of a satellite.

Unit-VII: Properties of Bulk Matter

Chapter 9: Mechanical Properties of Solids

Elasticity, Stress-strain relationship, Hooke’s law, Young’s modulus, bulk modulus, shear modulus of rigidity (qualitative idea only), Poisson’s ratio; elastic energy.

Chapter 10: Mechanical Properties of Fluids

Pressure due to a fluid column; Pascal’s law and its applications (hydraulic lift and hydraulic brakes), effect of gravity on fluid pressure.

Viscosity, Stokes’ law, terminal velocity, streamline and turbulent flow, critical velocity, Bernoulli’s theorem and its applications.

Surface energy and surface tension, angle of contact, excess of pressure across a curved surface, application of surface tension ideas to drops, bubbles and capillary rise.

Chapter 11: Thermal Properties of Matter

Heat, temperature,( recapitulation only) thermal expansion; thermal expansion of solids, liquids and gases, anomalous expansion of water; specific heat capacity; Cp, Cv – calorimetry; change of state – latent heat capacity.

Heat transfer-conduction, convection and radiation (recapitulation only), thermal conductivity, qualitative ideas of Blackbody radiation, Wein’s displacement Law, Stefan’s law.

Unit-VIII: Thermodynamics

Chapter 12: Thermodynamics

Thermal equilibrium and definition of temperature (zeroth law of thermodynamics), heat, work and internal energy. First law of thermodynamics, Second law of thermodynamics: gaseous state of matter, change of condition of gaseous state -isothermal, adiabatic, reversible, irreversible, and cyclic processes.

Unit-IX: Behaviour of Perfect Gases and Kinetic Theory of Gases

Chapter 13: Kinetic Theory

Equation of state of a perfect gas, work done in compressing a gas.

Kinetic theory of gases – assumptions, concept of pressure. Kinetic interpretation of temperature; rms speed of gas molecules; degrees of freedom, law of equi-partition of energy (statement only) and application to specific heat capacities of gases; concept of mean free path, Avogadro’s number.

Unit-X: Oscillations and Waves

Chapter 14: Oscillations

Periodic motion – time period, frequency, displacement as a function of time, periodic functions and their application.

Simple harmonic motion (S.H.M) and its equations of motion; phase; oscillations of a loaded spring- restoring force and force constant; energy in S.H.M. Kinetic and potential energies; simple pendulum derivation of expression for its time period.

Chapter 15: Waves

Wave motion: Transverse and longitudinal waves, speed of travelling wave, displacement relation for a progressive wave, principle of superposition of waves, reflection of waves, standing waves in strings and organ pipes, fundamental mode and harmonics, Beats.

Students can also access the syllabus for other subjects by visiting Syllabus page of CBSE Class 11.

CBSE Syllabus for Class 11 Physics Practical

Below are the list of the experiments of Physics practicals.

Evaluation Scheme for Class 11 Physics Practical 2023-24

CBSE Class 11 Physics Practical Syllabus

Section – A

CBSE 11 Physics Syllabus Experiments 

1. To measure the diameter of a small spherical/cylindrical body and to measure internal diameter and depth of a given beaker/calorimeter using Vernier Callipers and hence find its volume.
2. To measure the diameter of a given wire and thickness of a given sheet using screw gauge.
3. To determine the volume of an irregular lamina using the screw gauge.
4. To determine the radius of curvature of a given spherical surface by a spherometer.
5. To determine the mass of two different objects using a beam balance.
6. To find the weight of a given body using parallelogram law of vectors.
7. Using a simple pendulum, plot its L-T² graph and use it to find the effective length of second’s pendulum.
8. To study variation of time period of a simple pendulum of a given length by taking bobs of same size but different masses and interpret the result.
9. To study the relationship between force of limiting friction and normal reaction and to find the co- efficient of friction between a block and a horizontal surface.
10. To find the downward force, along an inclined plane, acting on a roller due to gravitational pull of the earth and study its relationship with the angle of inclination θ by plotting graph between force and sin θ.

CBSE 11 Physics Syllabus Activities

1. To make a paper scale of given least count, e.g., 0.2cm, 0.5 cm.
2. To determine mass of a given body using a metre scale by principle of moments.
3. To plot a graph for a given set of data, with proper choice of scales and error bars.
4. To measure the force of limiting friction for rolling of a roller on a horizontal plane.
5. To study the variation in range of a projectile with angle of projection.
6. To study the conservation of energy of a ball rolling down on an inclined plane (using a double inclined plane).
7. To study dissipation of energy of a simple pendulum by plotting a graph between square of amplitude and time.

Section – B

CBSE 11 Physics Syllabus Experiments 

1. To determine Young’s modulus of elasticity of the material of a given wire.
2. To find the force constant of a helical spring by plotting a graph between load and extension.
3. To study the variation in volume with pressure for a sample of air at constant temperature by plotting graphs between P and V, and between P and 1/V.
4. To determine the surface tension of water by capillary rise method.
5. To determine the coefficient of viscosity of a given viscous liquid by measuring terminal velocity of a given spherical body.
6. To study the relationship between the temperature of a hot body and time by plotting a cooling curve.
7. To determine specific heat capacity of a given solid by method of mixtures.
8. To study the relation between frequency and length of a given wire under constant tension using sonometer.
9. To study the relation between the length of a given wire and tension for constant frequency using sonometer.
10. To find the speed of sound in air at room temperature using a resonance tube by two resonance positions.

CBSE 11 Physics Syllabus Activities

1. To observe change of state and plot a cooling curve for molten wax.
2. To observe and explain the effect of heating on a bi-metallic strip.
3. To note the change in level of liquid in a container on heating and interpret the observations.
4. To study the effect of detergent on surface tension of water by observing capillary rise.
5. To study the factors affecting the rate of loss of heat of a liquid.
6. To study the effect of load on depression of a suitably clamped metre scale loaded at (i) its end (ii) in the middle.
7. To observe the decrease in pressure with increase in velocity of a fluid.

Practical Examination for Visually Impaired Students of Class 11 Evaluation Scheme

Time: 2 Hours
Max. Marks: 30

A. Items for Identification/Familiarity of the apparatus for assessment in practicals (All experiments). 

Spherical ball, Cylindrical objects, vernier calipers, beaker, calorimeter, Screw gauge, wire, Beam balance, spring balance, weight box, gram and milligram weights, forcep, Parallelogram law of vectors apparatus, pulleys and pans used in the same ‘weights’ used, Bob and string used in a simple pendulum, meter scale, split cork, suspension arrangement, stop clock/stop watch, Helical spring, suspension arrangement used, weights, arrangement used for measuring extension, Sonometer, Wedges, pan and pulley used in it, ‘weights’ Tuning Fork, Meter scale, Beam balance, Weight box, gram and
milligram weights, forceps, Resonance Tube, Tuning Fork, Meter scale, Flask/Beaker used for adding water.

B. List of Practicals

1. To measure diameter of a small spherical/cylindrical body using vernier calipers.
2. To measure the internal diameter and depth of a given beaker/calorimeter using vernier calipers and hence find its volume.
3. To measure diameter of given wire using screw gauge.
4. To measure thickness of a given sheet using screw gauge.
5. To determine the mass of a given object using a beam balance.
6. To find the weight of given body using the parallelogram law of vectors.
7. Using a simple pendulum plot L-T and L-T2 graphs. Hence find the effective length of second’s pendulum using appropriate length values.
8. To find the force constant of given helical spring by plotting a graph between load and extension.
9. (i) To study the relation between frequency and length of a given wire under constant tension using a sonometer.
(ii) To study the relation between the length of a given wire and tension, for
constant frequency, using a sonometer.
10. To find the speed of sound in air, at room temperature, using a resonance tube, by observing the two resonance positions.

Note: The above practicals of CBSE 11 Physics Syllabus may be carried out in an experiential manner rather than recording observations.

Did you find CBSE 11 Physics Syllabus useful for your studies? Do let us know your view in the comment section. Get access to interactive lessons and videos related to CBSE Maths and Science with ANAND CLASSES (A School Of Competitions) – The Learning App. 

Frequently Asked Questions on CBSE Class 11 Physics Syllabus

Q1

According to the CBSE Class 11 Physics Syllabus, which are the units of high marks weightage?

According to the CBSE Class 11 Physics Syllabus, physical world and measurement, kinematics and laws of motion are the units of high-mark weightage.

Q2

How is the practical syllabus of the CBSE Class 11 Physics divided into sections A and B?

The practical syllabus of the CBSE Class 11 Physics contains 10 experiments in section A and 10 experiments in section B with 7 physical activities mentioned for each.

Q3

Which are the basic concepts present in the CBSE Syllabus for Class 11 Physics?

The basic concepts present in the CBSE Syllabus for Class 11 Physics are Thermodynamics, Laws of Motion, Oscillations and Waves.