DoE Online Classes

Date : September 8, 2020

Class : XI
Subject : PHYSICS
Chapter : PHYSICAL WORLD
Teacher : MANOJ SHARMA
RPVV, Sec 10 Dwarka
 TEAM PHYSICS
Mr. MANOJ Dr. ARVIND Ms. Sarita
SHARMA, PGT KUMAR Saxena, PGT
Physics (Coordinator) Physics
RPVV, Sec 10 CAU (Dte. Of RPVV, IP Extn
Dwarka (Dte. Of Education (Dte. Of
Education) Education)

Mr. Prabha Mr. Gautam Mr. Akash

Kant Nautiyal, PGT Aneja PGT
Sharma,PGT Physics Physics
Physics SOE, Sec 22, SOE,
R.P.V.V. Dwarka (Dte. Madanpur
Kishan Ganj Of Education) Khadar
(Dte. Of (Directorate of
Education)
Education)
 Guidelines for Students
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 Guidelines for Students
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and PDF notes.

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or hear properly.

Use chat box only for asking doubts and do

not indulge in unnecessary chats
 Syllabus(Theory)
UNITS CHAPTERS MARKS
Unit–I Physical World and Measurement
Chapter–1: Physical World
Chapter–2: Units and Measurements
Unit-II Kinematics
23
Chapter–3: Motion in a Straight Line
Chapter–4: Motion in a Plane
Unit–III Laws of Motion
Chapter–5: Laws of Motion
 Syllabus (Theory)
UNITS CHAPTERS MARKS
Unit–IV Work, Energy and Power
Chapter–6: Work, Energy and Power
Unit-V Motion of System of Particles and Rigid Body

17
Chapter–7: System of Particles and Rotational
Motion
Unit- VI Gravitation
Chapter–8: Gravitation
 Syllabus (Theory)
UNITS CHAPTERS MARKS
Unit–VII Properties of Bulk Matter
Chapter–9: Mechanical Properties of Solids
Chapter–10: Mechanical Properties of Fluids
Chapter–11: Thermal Properties of Matter
Unit-VIII Thermodynamics 20
Chapter–12: Thermodynamics
Unit–IX Behaviour of Perfect Gases and Kinetic
Theory of Gases
Chapter–13: Kinetic Theory
 Syllabus (Theory)
UNITS CHAPTERS MARKS
Unit–X Oscillations and Waves
Chapter–14: Oscillations 10
Chapter–15: Waves
Total 70
 Syllabus (Practical)
❖ SECTION–A
Experiments

To measure 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.
To measure diameter of a given wire and thickness of a given sheet using
screw gauge.
To determine volume of an irregular lamina using screw gauge.
To determine radius of curvature of a given spherical surface by a
spherometer.
To determine the mass of two different objects using a beam balance.
To find the weight of a given body using parallelogram law of vectors.
 Syllabus (Practical)
Using a simple pendulum, plot its L-T2 graph and use it to find the
effective length of second's pendulum.

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

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.

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 sinθ.
 Syllabus (Practical)
Activities

To make a paper scale of given least count, e.g., 0.2cm, 0.5 cm.
To determine mass of a given body using a metre scale by principle of
moments.
To plot a graph for a given set of data, with proper choice of scales and
error bars.
To measure the force of limiting friction for rolling of a roller on a
horizontal plane.
To study the variation in range of a projectile with angle of projection.
To study the conservation of energy of a ball rolling down on an inclined
plane (using a double inclined plane).
 Syllabus (Practical)
SECTION–B

Experiments

To determine Young's modulus of elasticity of the material of a given wire.

To find the force constant of a helical spring by plotting a graph between
load and extension.
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.
To determine the surface tension of water by capillary rise method.
To determine the coefficient of viscosity of a given viscous liquid by
measuring terminal velocity of a given spherical body.
 Syllabus (Practical)
SECTION–B

To study the relationship between the temperature of a hot body and time
by plotting a cooling curve.
To determine specific heat capacity of a given solid by method of
mixtures.
To study the relation between frequency and length of a given wire under
constant tension using sonometer.
To study the relation between the length of a given wire and tension for
constant frequency using sonometer.
To find the speed of sound in air at room temperature using a resonance
tube by two resonance positions
 Syllabus (Practical)
SECTION–B
Activities

To observe change of state and plot a cooling curve for molten wax.
To observe and explain the effect of heating on a bi-metallic strip.
To note the change in level of liquid in a container on heating and interpret
the observations.
To study the effect of detergent on surface tension of water by observing
capillary rise.
To study the factors affecting the rate of loss of heat of a liquid.
To study the effect of load on depression of a suitably clamped metre
scale loaded at (i) its end (ii) in the middle.
To observe the decrease in pressure with increase in velocity of a fluid.
CHAPTER 1
 Topics to be discussed
• What is Science ?
• Scientific method.
• What is Physics ?
• Scope and excitement of Physics.
• Physics, Technology and Society.
• Fundamental forces in nature
• Nature of Physics laws.
 • The word science is originated from a Latin
word scientia which means ‘to know’.
• The sciences which deal with non-living
things are called physical sciences.
Examples of physical sciences are physics,
chemistry, geography, astronomy and
oceanology
• The sciences which deal with living things
are called biological sciences . Examples
are zoology, botany…….
 SCIENTIFIC METHOD
OBSERVATION VERIFICATION

QUESTION PREDICTION

HYPOTHESIS MATHEMATICAL
MODELLING

QUANTITATIVE AND
EXPERIMENTS QUALITATIVE REASONING
❖The word Physics comes from a Greek word Phusis meaning NATURE.

❖ Its Sanskrit equivalent is Bhautiki that is used to refer to the study of the
physical world.

❖Physics is the study of nature and natural phenomena..

❖Physics deals with certain basic rules/laws governing the natural world .

❖Precisely Physics is a study of the basic laws of nature and their

manifestation in different natural phenomena
 Two basic approaches in Physics
Two basic thrusts in Physics

UNIFICATION REDUCTION
An attempt to explain diverse physical An attempt to derive the properties of
phenomena in terms of few concepts and laws a bigger, more complex system from
is called unification the properties and interaction of its
For example, fall of an apple and motion of constituent simpler parts is called
planets around the sun ,both the phenomena reductionalism
can be explained by a single law given by
Newton – The universal law of gravitation.
 SCOPE OF PHYSICS

Two Domains of physics

Macroscopic Microscopic
Macroscopic Phenomena are the Microscopic Phenomena are the
phenomena which take place at phenomena which take place at molecular,
laboratory, terrestrial or astronomical atomic and nuclear level
scales.
Classical Physics Modern Physics
Usually classical physics refers to pre- This domain of physics refers to post-
1900 physics 1900 physics
 Classical Physics
Classical Physics deals mainly with macroscopic
phenomena and includes following sub disciplines

1…Mechanics
2…Electrodynamics
3…Optics
4…Thermodynamics
 Mechanics
Branch of Classical Physics which deals with the motion and forces on bodies and
founded on Newton's laws of motion and law of gravitation.
 Optics
Optics deals with various phenomena associated with light. For ex- reflection,
refraction, interference, diffraction and polarization.
 Electrodynamics
This branch deals with electric and magnetic phenomena associated with charged
and magnetic bodies. Electrodynamics is largely based on laws given by Coulomb,
Oersted, Ampere and Faraday. In fact everything can be unified in terms of Maxwell's
equations
 Thermodynamics
It deals with changes in internal energy, temperature, entropy through external work
and transfer of heat.
 Modern Physics
Modern Physics refers to post-1900 physics and includes following
sub-disciplines:

Quantum Mechanics : deals mainly with microscopic phenomena

Relativity
Excitement of Physics
 Physics and Technology
Technology Scientific principle

Steam engine Laws of thermodynamics

Nuclear reactor Controlled nuclear fission

Radio and television Generation, propagation and detection of

electromagnetic waves

Computers Digital logic

Rocket propulsion Newton’s laws of motion

Electric generator Faraday’s laws of electromagnetic induction

Aeroplane Bernoulli’s Principle in fluid dynamics

Optical fibres Total internal reflection of light

 FUNDAMENTAL FORCES IN NATURE
There are four fundamental forces in nature, which are described in brief here:
1. Gravitational Force
The gravitational force is the force of mutual attraction between any two objects by virtue of
their masses.
It is a universal force.
All Objects on earth experience the force of gravity due to the earth.
Gravitational force governs the motion of moon and artificial satellites around earth, motion of
planets around sun.
It is the weakest fundamental force.
It has infinite range.
 2. Electromagnetic Force
Electromagnetic force is the force between charged particles.
There are two cases:
1. The force between two static charges ( Coulomb’s Law). Attractive for unlike charges and
Repulsive for like charges.
2. Charges in motion produce magnetic effects and a magnetic field and a magnetic field
gives rise to a force on moving charges.
Electric and magnetic effects are generally inseparable and hence termed as
electromagnetic force.
Like gravitational forces electromagnetic forces also act over large distances.
It is mainly electromagnetic force that governs the structure of atoms and molecules,
chemical reactions and mechanical, thermal and other properties of materials.
It also underlines the macroscopic forces like friction and spring forces.
 3. Strong Nuclear Force
The force between nucleons ( proton-proton, proton-neutron, neutron-neutron) within the
nucleus.
Strongest force in nature.
It is a charge independent force.
Its range is very small and operational within the nucleus only.
The electron does not experience this force.
 4. Weak Nuclear Force
It appears only in certain nuclear processes such as 𝛃-decay.
This force is weaker than strong nuclear force and electromagnetic force but stronger than
gravitational force.
The range of this force is very small like nuclear force.
 Comparison amongst fundamental forces of nature

Name Relative Strength Range Operates among

Gravitational 10¯³⁹ Infinite All objects in the universe

Elementary particles like

Weak nuclear force 10¯¹³ Very short(∼10¯¹⁶)
electron and neutrino

Electromagnetic force 10¯² Infinite Charged particles

Very short(∼10¯¹⁶)
Strong nuclear force 1 Nucleons
 Nature of Physical Laws
In any physical phenomenon governed by different forces several quantities may change
with time though there are some special physical quantities which remain constant in time.
These quantities are called conserved quantities of nature.
There are various conservation laws in physics:

1. Law of conservation of energy

2. Law of conservation of linear momentum

3. Law of conservation of angular momentum

4. Law of conservation of charge

 HOMEWORK

PREPARE LIFE SKETCHES OF PROMINENT PHYSICISTS.