QUALITY ENHANCEMENT
IN
PHYSICS
For PGT’s
2009
STATE COUNCIL OF EDUCATIONAL RESEARCH AND TRAINING
Chief Advisor
Rakesh Mohan, IAS
Principal Secretary (Education)
GNCT of Delhi-cum-Chairperson, SCERT
Guidance
Chandra Bhushan Kumar, IAS
Director (Education) GNCT of Delhi
Rashmi Krishnan, UTCS
Director, SCERT
Daljeet Kaur
Additional Director, SCERT
Dr. Pratibha Sharma
Joint Director, SCERT-cum-State Pedagogy Coordinator
Dr. Pawan Sudhir
Secretary, SCERT
Course Director / Coordinator
Dr. Charu Varma
Lecturer (Science), D.I.E.T., Pitampura, Delhi
Member of Writing Team
Prof. N. K. Sehgal
Reader, Hans Raj College, Delhi University
Dr. Charu Varma
Lecturer (Science), D.I.E.T., Pitampura
Dr. Pundrikaksh
Vice-Principal, DOE, Delhi
Mr. C. B. Verma
Retd. Principal
Dr. (Mrs.) Santosh Verma
PGT (Physics),
G.G.S.S.S. D.O.E., Delhi
Mr. R. Rangarajan
HOD (Physics), DTEA Sr. Sec. School
Laxmi Bai Nagar, New Delhi
Chief Editor
Dr. Charu Varma
Mukesh Yadav, Publication Officer. State Council of Educational Research & Training, New Delhi
Printed at Ankur Offset & Packaging, New Delhi
List of Contents
S. No.
1.
2.
Topic
Meaning of Physics & Course Structure
Teaching Physics - The Essenthils
Page No.
1
3
3.
Increase your work efficiency
4
4.
The Car & The Wall - Law of Inertia
5
5.
Radioactivity
6
6.
Heat & Thermodynamics
10
7.
Magnetism made Simple
22
8.
Problem of Absenteeism
25
9.
Help yourself & your Students via Goal Setting.
27
10.
‘HOTS’ in Physics
29
11.
Examples of ‘HOTS’
30
12.
Career opportunity in Physics
39
13.
Appendix:
40
A - Life of Science (Physics) Articles
B - Proforma of Condenmation
Proforma of Condenmation
43
Suggested Readings
45
Net Resources
45
List of Counselors
46
List of Sessions to be coursed
46
MEANING OF PHYSICS & COURSE STRUCTURE
The term "Physics" has been derived from a Greek word meaning "natural things".
Physics is the science devoted to the study of matter and energy. Physicists try to understand
what matter is all about and its behavioral pattern. They seek to learn how energy is produced,
its mode of travel from one place to another and the mechanism of its control. They also study
the relationship between matter and energy. The subject may be grouped into two broad
categories, viz., theoretical physics and experimental physics. Theoretical physics deal with
laws and theories which are almost always expressed in the language of mathematics, and
therefore mathematics is the basic tool of physics. Experimental physics involves carefully
designed experiments and comparison of the findings with the predictions based on the theory
and laws propounded by theoretical physicists.
The subjects studied by physicists may also be grouped into two broad categories, viz.,
classical physics and modern physics. They differ only in terms of emphasis and therefore,
interrelated. Classical physcis is concerned with motion and energy and consists of five basic
areas, viz., (1) Mechanics, (2) Heat, (3) Sound, (4) Light, and (5) Electricity and Magnetism.
Modern physics primarily concentrates on the basic structure of the material world. The major
fields include (1) Atomic, Molecular, and Electron Physics, (2) Nuclear Physics, (3) Particle
Physics, (4) Fluid and Plasma Physics, and (5) Solid State Physics.
The Board's Syllabus in the subject at Senior Secondary Stage has been prepared
keeping in view the rigor and depth of disciplinary approach as well as comprehension level of
the learners. Besides laying emphasis on conceptual understanding of different content areas,
it also aims at promoting process skills and problem solving abilities in the learners.
The syllabus comprises of two components - theory and practical work.
Theory - 70% weightage.
Practical work - 30% weightage.
An effort has been made to relate the two components as closely as possible. The
syllabus has been divided into few broad and separate areas of study.
The following table conveys comprehensive information of these different broad fields.
S.NO.
CLASS XI
CLASS XII
1.
Mechanics
Electricity
2.
Heat
Magnetism
3.
Matter
Optics
4.
Vibrations
Atoms & Nuclei
5.
–
Devices & Communication System
Physics attempts to answer interesting and intriguing questions that arise
from our daily life observations. It is undoubtedly most fundamental science that
helps us to get a better understanding of the physical world and to acheive
progress - farther and faster!
1
The Wikipedia encyclopedia considers Physics as the branch of science
concerned with the discovery and characterization of universal laws which
govern matter, energy, space and time. The role of Physics, it states, is to
provide a logical pricture of nature, in agreement with experience.
There is no change in the syllabus for the session 2009-10 as per
C.B.S.E. website information.
Note : The Board reserves the right to amend the Syllabi and Courses as
and when it deems necessary. The Schools are required to strictly follow
the Syllabi and textbooks prescribed by the Board for the academic
sessions and examinations concerned. No deviation is permissible.
Class XI & Class XII (Theory Paper of 3 hours Max Marks : 70)
Class XI
Weightage
Unit I
Physical World & Measurement
03
Unit II
Kinematics
10
Unit III
Laws of Motion
10
Unit IV
Work, Energy & Power
06
Unit V
Motion of System of Particles & Rigid Body
06
Unit VI
Gravitation
05
Unit VII Properties of Bulk Matter
10
Unit VIII Themodynamics
05
Unit IX
Behaviour of Perfect Gas & Kinetic Theory of gases
05
Unit X
Oscillations & Waves
10
Class XII
Weightage
Unit I
Electrostatics
08
Unit II
Current Electricity
07
Unit III
Magnetic effect of current & Magnetism
08
Unit IV
Electromagnetic Induction and Alternating current
08
Unit V
Electromagnetic Waves
03
Unit VI
Optics
14
Unit VII Dual Nature of Matter
04
Unit VIII Atoms and Nuclei
06
Unit IX
Electronic Devices
07
Unit X
Communication Systems
05
Recommended Textbooks :
2
1.
Physics Part-I & Physics Part-II Textbooks for Class XI, Published by NCERT
2.
Physics Part-I & Physics Part-II, Textbook for XII, Published by NCERT
Teaching Physics - The Essentials (Source : www.cbse.nic.in)
Physics is a fascinating and interesting subject. A teacher needs to create a suitable
ambience for learning. Einstein once remarked "I never teach my pupils. In only attempt to
provide the conditions in which they can learn."
The following considerations are likely to help any physics teacher :
•
Introduce the topic by asking simple questions which are directly related to everyday
observations or may arouse interest for learning of the topic e.g. before teaching the topic on
diffraction, the question : - 'Why does the color of the butterfly wing depend on the angle at
which it is viewed', may arouse interest for the topic amongst the learners.
•
Asking thought-provoking questions in the class and, in turn, encouraging the students to ask
questions can keep them mentally alert resulting in better understanding of concepts.
•
Relating concepts to relevant daily life situations and practical applications may enable them
apreciate and understand the subject better.
•
A reasonable knowledge of basic mathematical concepts and formulae from Algebra,
Geometry and Trigonometry is an essential prerequisite for learning of Physics. Remedial
measures may be taken, if need be.
•
Physics is not just equations and relations. It is equally important to understand the physical
significance of these relations.
•
Drawing of graphs and correct interpretation of graphs form an equally essential component
of learning of Physics. This aspect deserves to find a suitable place and emphasis in
classroom teaching.
•
Occasional demonstrations and asking students to perform activities would greatly enhance
the depth of learning and understanding of concepts.
Theory
and Practical
worktwo
areintegral
two integral
and complementary
components
Theory
and Practical
work are
and complementary
components
of learning of
of
learning
of
Physics.
The
practical
work
deserves
to
be
due
emphasis
Physics. The practical work deserves to be due emphasis and recognition. and
recognition. Theory and
3
Increase your work efficiency-create the right environment
Get comfortable, and eliminate distraction from your environment.
Rearrange your working environment so that you eliminate as many
distractions as possible.
•
Keep interruptions at bay. Put up the "Do not disturb" sign, switch off
your cell phone, close your email reader and web browser, and do
anything. Anything that will block the most common things that distract
you from work.
•
Manage your stress. Identify the sources of stress you experience. And
then work to reduce or eliminate the greatest stressors. One of the most
common sources of stress at work is feeling that you have too much to
do.
•
Keep a To-Do List or Action Program. Empty your mind of those
distracting things you have to do by writing them down in a to-do list or
action program. You'll be amazed how much this can clear your mind!
Do the same for worries write them down and schedule a time to deal
with them. And don't try to multitask : Just concentrate on doing one
thing well.
•
Think positively. It's very hard to concentrate if you have negative thoughts
swirling around your mind. What's more, the negativity they cause
undermines the way we deal with work, with people and with issues, often
making things more difficult. So the final step in preparing to concentrate is to
stop thinking negatively and start thinking positively.
4
The Car and the Wall - Law of Inertia
According to Newton's first law, an object in motion continues in motion with
the same speed and in the same direction unless acted upon by an unbalanced
force. It is the natural tendency of objects to keep on doing what they're doing. All
objects resist changes in their state of motion. In the absence of an unbalanced
force, an object in motion will maintain its state of motion. This is often called the
law of intertia.
The law of inertia is most commonly experienced when riding in cars and
trucks. In fact, that tendency of moving objects to continue in motion is a
common cause of a variety of transportation injuries - of both small and large
magnitudes. Consider for instance the unfortunate collision of a car with a wall.
Upon contact with the wall, an unbalanced force acts upon the car to abruptly
decelerate it to rest. Any passengers in the car will also be decelerated to rest if
they are strapped to the car by seat belts. Being strapped tightly to the car, the
passengers share the same state of motion as the car. As the car accelerates the
passengers accelerate with it; as the car decelerates, the passengers decelerate
with it; and as the car maintains a constant speed, the passengers maintain a
constant speed as well.
But what would happen if the passengers were not wearing the seat belt?
What motion would the passengers undergo if they failed to use their seat belts
and the car was brought to a sudden and abrupt halt by a collision with a wall?
Were this scenario to occur, the passengers would no longer share the same
state of motion as the car. The use of the seat belt assures that the forces
necessary for accelerated and decelerated motion exist. Yet, if the seat belt is
not used, the passengers are more likely to maintain its state of motion.
If the car were to abruptly stop and the seat belts were not being worn, then
the passengers in motion would continue in motion. Assuming a negligible
amount of friction between the passengers and the seats, the passengers would
likely be propelled from the car and be hurled into the air. Once they leave the
car, the passenger becomes projectiles and continues in projectile-like motion.
”Now perhaps you will be convince of the need to wear your seat belt.”
5
Radioactivity (Source : Splung.com physics)
Introduction
In 1896, Bequerel, a French physicist disovered that crystals of Uranium salts emitted
penetrating rays similar to X-rays which could fog photographic plates. Two years after this
Pierre and Marie Currie discovered other elements : Polonium and Radium which had this
property. The emission was known as Radioactivity.
Stability of Nuclei
Protons and Netrons are held together in the nucleus of an atom by the strong-force.
This force acts over a very short distance of about - 1 fm. (10-15m) and over this short
distance it can overcome the electromagnetic repulsion between the positively charged
protons. Nuclei with radii that are within the range of the Strong force are stable. As atomic
number increases the radius of the nucleus also increase and the element becomes
unstable. This instability manifests itself as the emission of particles or energy from the
nucleus. The elements with atomic number greater than 82 are radioactive.
Decay Constant
The decay constant is a measure of how quickly on average a radioactive nuclei will
take to decay. Since radioactive decay is a random process, the decay of a single nucleus
may happen at any time but for many undecayed nuclei, the average decay rate is given by
the decay constant, l and it has the unit of [s–1] or [h–1] or [year–1].
Activity
The activity of a radioactive material is defined by two factors :
1. the number of undecayed atoms, N
2. the decay constant, l
The activity, A is measured in Becquerels [Bq] or [s–1].
A = ‫ג‬N
The corrected activity is the activity taking into account the background radiation.
Radioactive Decay
Consider a block of radioactive material, initially the number of undecayed nuclei is,
N0. On the basis of our reasoning above we can say that the number which will decay will
depend on overall number of nuclei, N, and also on the length of the brief period of time. In
other words the more nuclei there are the more will decay and the longer the time period
the more nuclei will decay. Let us denote the number which will have decayed as dN and
the small time interval as dt. So we have reasoned that the number of radioactive nuclei
which will decay during the time interval from t to t+dt must be proportional to N and to dt.
In symbols therefore : –dNµNdt. Turning the proportionality in this equation into an equality
we can write : -dN= Ndt.
6
Dividing across by N we can rewrite this equation as:
dN
= λ dt
N
So this equation describes the situation for any brief time interval, dt. To find
out what happens for all periods of time we simply add up what happens in each
brief time interval. In other words we integrate the above equation. Expressing
this more formally we can say that for the period of time from t = 0 to any later
time t, the number of radioactive nuclei will decrease from N0 to Nt so that :
Nt dN
t
−∫
λdt
N0
N ∫0
Nt
= exp ( −λdt)
N0
Nt = N0 exp ( −λt)
The Final expression is known as the radioactive decay law. It has the form
of an exponential decay curve like the one we saw in the discharge of a
capacitor.
Half - Life
The
decay law leads
to an exponential decay which reaches zero in an infinite amount of time. A
useful measure of rate at which the material decays is given by the half-life. This
is the time taken for the number of undecayed nuclei to decrease by half the
initial amount.
7
Half-life of a radioactive decay curve
Sucessive half-lifes decreases the number of undecayed nuclei by N0/4,
N0/8 etc. as shown in figure.
Successive half-lives decrease the number of undecayed nuclei by half each time
Mathematically, the half-life can be calculated by seting Nt = N0/2 in the
radioactive decay equation. Therefore, N0/2=N exp (-lambda t½). Taking logs
and re-arranging for t½ leads to t½ = ln(2)/l
Modes of Radioactive Decay
There are broadly three types of radioactive emissions. These are :
α radiation
Alpha radiation is the emission of two protons and two neutron from the
nucleus, which is the same as a Helium nucleus. Due to the heavy mass and
charge, a radiation the least penetrating, being stopped by a sheet of paper.
However it also is the most ionising form of radiation, knocking electrons from
their shells in nearby atoms. The dangers of alpha-radiation come from being
ingested into the body. When an alpha particle is emitted, the proton number
decreases by 2 and mass number decreases by 4.
A X ® A-4
4
Z
Z-2 (X–2) + 2a
ß radiation
ß radiation is the emission of an electron from the nucleus. Since the
nucleus does not contain any electrons, either a proton or a neutron transforms.
Depending on which transform leads to one of two kinds of beta radiation.
Beta radiation occurs in two forms. ß + and ß –.
•
•
ß + a positive electron called a positron is created by the transformation of a
proton into a neutron.
AZX ® AZ (X–1) + 0 e + 0 n
-1
+1
0
ß – the electron is created by the transformation of a proton into a neutron.
AZX ® AZ (X–1) + 0 e– + 0 n;
+1
–1
0
8
9
HEAT AND THERMODYNA-MICS
Heat : The energy (internal) is transferred from one body to another without any
mechanical work innolved is called heat.
Temperature : Of a body is the measure of level of heat.
System : The part of uninerse at which me do concentrate our efforts.
Surrownding : The part of uninerse at whech system has direct dependance.
Thermal Equilibrium : A system is said to be in thermal eqilibrium if there is no exchange
of heat between any two parts of the system.
Mechanical Equilibrium : A system in which there is no umbalamced force between two
parts of the system.
Mass Equilibrium : A system in which there is no exchange of matter between any two
parts of the system.
Thermodynamic Equilibrium : A system is said to be in thermodynamic equilibruim if it
has all the three equiliberanamely thermal, mechanical and ma
ss present in it.
Zeroth low of thermodymanics : Threebodies A, B and C are such thatA is in thermal equilibrium with B.
B is in thermal equilibrum with C then.
A will be in thermal equilibrium with C.
Thermomety : The study of measurement of level of heat with respect to a reference body.
Thermometric scale : In practical follwing scales are used with reference to metting ice.
and Boiling mater
Celsins
Fahrenheit
C
Metting ice
F
0
Kebrun
T
32
273.15
Boiling mater
100
212
373.15
Difference between
minimum and
Maximum Temp
100
180
100
C-0
F-32
T-273.15
=
=
100
180
100
Thermometre Properties : The praperty of a substance that changes on supplying heat to
it. eg. Length, Area, Volume, Pressure, Electrical resistenel.
the temperature measuring sange of a thermometer depends on the extent upto which the
thermometre property of substance used in thermometer changes linearly.
10
In a linear expansion thermometer
l t = l0 (1+ ∝ t)
(1)
l 2 = l1 (1+ ∝ ∆t)
(2)
∆t = t2 -t1 change in temperature expressed in C0 orkeluin lK)
Δl
Δl 0 -1
∝
=
C
(3)
lΔt
l 0t
1
∝ temperature coefficient of imeai expansion from above expression.
l100 =l0 ( 1+ ∝ ×100)
(1)
(4)
From (1) and (4) it con be unother then.
 l -l 
t =  t 0  × 100
 l100 -l0 
(5)
Proceeding in the same may the formula for temperature measurement can
be umtter for the thermometers based on the other thermometric properteis
e.g. Area, volume, pressure, Resistence etc.
β =
ΔA
AΔt
1
0
C-1
A 2 = A1 (1+BΔt),
γ =
ΔV
ΔV
=
,
VΔt
V 0t
1
At = A0 (1+Bt)
V2 = V1 (1+γΔt)
Vt = V0 (1+γt)
β =2∝
γ = 3∝
∝=
β γ
=
2 3
Triple Point : A point in P-T graphs for a substance haming pressure and
temperature such that all the three states v of the substance coexist.
(Sobil, liguid and gas)
Tt r = .01 0 C = 273.16 K
Pt r = .46 con of Hg.
for water
Triple Point Thermometer :
T ∝ Pt
Ttr ∝ Ptr
⇒
P
T
= t ⇒
Ttr
Ptr
Unknown temperature T is given by
11
P 
T=  t  Ttr
 Ptr 
Internal energy :- of a substafnce is the sum of kinetic and botental
everagies of the continents (atams and molewles) of the substance.
For an ideal gas internal enegy equals the sum of kinetic energies of the
molecules conctituting the gas. (Molecules of anideal gas neither athod nor
repel each other therefore their potential everage is zero) This energy is a
function of temprature only. 2nd systematic motor of the ideal gas internal
energy does not charge.
 ∆u 
  =0
U=f(T) =  ∆t 
for ideal gas.
Calori - Unit of heat - If is the amount of heat energy epmeid to change the
temperature of 1 gram of water by 1 C0 from 14.5 C0 to 15.5 C0.
1 Colori = 4.18 J ≈ 4.2 J.
Clorific Value :- of a substances is the amount of heat generated when unit
moss of the substance is burnt coopletely. Its unit is col/g
Heat capacity :- of a body is the amount of heat requred to change the
temperature of body by unity (1 C0 or 1 K)
ΔQ
C=
ΔT
Specific Heat :- Of a substance is the amount of heat requced to change
the temperature of unit mass of the substance by unity (1 C0 or 1 K)
ΔQ
J
col
col
C =
or
or
0
0
mΔT
g-C
gC
g-K
Motor Heat capacity
C =
ΔQ
nΔT
col
Mole-K
n → number of mole.
Dulong and petits law :
For all solids motor heat capacity is same at aromel room temperature and ghals 3 R i.e.
Cv = 3 R
J=
2 col
=
Mole-K
Mole-K
6 col
∴ Cv 3 × 2
Mole/K
Where
R = 8.31
12
For Mater
C v 4.23 =
1 col
gm/C 0
For Gases :- (Iebal gas) specific heat varies from 0 to infinity When an ideal gas is studied
under urtain conditions e.g.
(i)
At enstant nolenes spcific heat it CV and
(ii)
At constant pressure → specific heat is CP
∆Q P
CP =
n∆T
CP > CV
CV =
∆Q V
n∆T
CV > CV because at constant volume Δ V = 0, Therefore mork done
Δ W = FΔS = PA ΔS = PΔV = 0
Entire heat supplied is used up in changing internal every by sorne amant where as at
constant pressure ΔV ≠ 0 heat supplied is used up in changing internal energy by same
amount U and also in doing external mork Δ W.
Also
f → number of degrees of brecdom
f = 3 monoatomue gas C He
f =5 diatomic (H2, N2, O2 etc.)
f = 6 Triatomic or polyatermic non imear mole culr system uniar mole cular system
f=7
Law of Equapartitian aof energy :
Energy of a gas (ideal) is equally distributed in all degrees of freedom.
According to kinetic theory of gases mean kinetic energy of translation permole
3
E K = RT (Monoaterui gas)
2
1
E
3 RT
1
Energy ber mole per degree of freedom
EK = K =
= RT
f
2 3
2
11
f
Mean Kinetic energy of translation per mole for f degrees of freedom
E K = RT
f
Mean Kinitic enegry of translation per molecule
13
EK =
EK 3
= R BT
NA 2
Where NA → Avagadro number.
Boltz mamis KB =
constant.
EK =
R
J
= 1.38 × 10-23
NA
K
2
1
3
= mu = K B T
2
2
2
Root mean squared
Speed.Vrus ∝ T
ε K ∝ T.
U rus = u =
3
KB T
2
Kinetic interpretation of temperture.
Latnt Heat : Also korown as hidden heat. Latent heat of a substance is the amount of heat
requred to change the phase of nunit mass of substance at constant temperatureFrom solid → Liquid latent heat of busion (Lf)
From liguid → Gas → latent heat of Vapori - Zaton (LV)
Lf =
Qf
m
Qf =mLf
for water Qf =mLf
cal
L V =540
g
QV
Q V =mL V
m
Principle of calorimeters : Based on law of consemation of energy.
When two bodies of different temperatures are broerght incontact then Heat given by = Heat
taken by one body another body
m1 C1 ∆T1 = m2 C2 ∆T2
LV =
Solid → solid → liquid → liquid → vapour.
-T1 → 0 → 0 → T2 → T2
(Melting) Boiling
Q1 Q2 Q3 Q4
Here Q1 = m C1 ∆T1 m → mars of substance
C → specific heat in solid state.
Q2 = mLf
Q3 = m C2 ∆ T2 C2 → C2 → Specific heat of substance in lequid state
Q9 = mLV.
Net heat innolved in the process
Q = Q1 + Q2 + Q3 + Q4.
Q = mC1 ∆T1 mLf + mC2 ∆T2 + mLV.
14
Work Done with expemsion (or Compression) of gas :
Consider n mole of anideal gas in a cylinder with perfectly
insulated mall and condneting base fitted with frictionless
piston of area A and over wheet prssure is P Work Done in
small displacement ∆X
∆W = F∆XX = P∆V
First law of Theronodynamics :
Heat ∆Q given to a system (ideal gas) is used up (i)
inchanging internal energy ∆u
(ii) indoing external mark ∆W.
∆Q = ∆Y+W = ∆U+ P∆Y
Sign conversion Heat gweirtoa system +
Heat taken out of system Work done bytho system +
Work done on the system State coordinates P, V, T and U.
Equation of state PV = nRT
n → number of mole
n=
M
M0
Mo → Molecular mass of gas
M → given mass of the gas. (ideal)
Isothermol Process : A process inwhich temperature T of the system (ideal gas) remamis
constant i.e. ∆T=0 change in internal energy ∆U=0
PV = const.
1
P∝
V
From first law of thermodynamcis.
∆Q=∆U+W = O+W = W.
Work done in ‘l’ sothermal process (area under PV Graph.)
15
V2
∫ PdV
W=
V1
Wisothermal =
V 
nRT ln  2 
 V1 
V 
=2.303 nRT log 10  2 
 V1 
Adiabatic Process : The preress carried out on a system in which it does not exchange heat
with the surromding l.e. ∆Q = 0
From I law
∆Q=∆U+W
0=∆U+W
=nCV ∆T+P∆V
Relations in P, V and T for adiabatic process
PV r =Constant
TV r =Constant
Tr
=Constant
P r-1
1
Vr
Work done in adiabatic
V∝
process
Wadea =
nR
1
T1 -T2 ] =
[
[ P1 V1 -P2 V2 ]
r-1
r-1
Isocheric Process : Change in volume. of the system is zero. i.e. ∆V=0
W = P∆V=0
from I low ∆Q = ∆U = nCV ∆T
P ∝ T
for given mass of ideal gas
16
Isobasic Process :
A process inmpeet pressure remams enstant.
V ∝ T
Work Done Wi isobaric process
Wisobame = P∆V=P(V2-V1)
∆Q= ∆U+W ∆nCP ∆T= nCV ∆T+P∆V
When all the pracesses aretaben together on a PV
graph.
1 → isobaric pracess
2 → Isothermal pracess
3 → adiabatic pracess
4 → isochoric. pracess
From graphs it follows that.
Wisoberic > Wisothemal > Wadiabatic > Wisocharic
Engine : A machine that converts one form of
energy
into useful work.
Heat Engine :- converts heat into useful work.
Main Parts of Heat Engine.
1 Source - A hot body at temperature T1 and
infinite heat capacity.
2 Sink - Cold body at temperature T2 (CT1) also of infinite heat capacity.
haring
3 Working substance - A body that takes in heat Q1 from source at temperature T1.
converts a pent of that in to useful work W and rejects the remaining heart Q2 to sink.
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Carnot Engine :- Based on Carnot cycle in which the inorking substance is subjected to
following four processes area. cycle.
AB → isothermal expansion
BC → Adiabatic expansion
CD → isothemal compression
DA → adiabatic compression.
Work Done in complete cycle is the area enclosed
graphs.
by the P.V.
V 
W = nr(T1 -T2 ) ln  2 
 V1 
For process AB ∆UAB = 0 ( temp. is constant)
From I law ∆QAB = ∆UAB+WAB
Q1 = 0+WAB = WAB
Q1 = nRT1 ln
 V2 
 V 
1
Elticeniy
e =
W
T
= 1- 2
Q1
T1
Carnot
theorean :- All engines working between same temperatures T1
and T2 of source and sink are equally efficient errespeetmix of nature of unworking substance.
Refrigerator :- Also known as heat pump.
Main parts - cold bodysat temperature T2 Hot bodys at temprature T1
working substanes - ideal gas.
In a refrigerator work is dorp or working substance, which withdraws
heat Q2 from cold body and rycets heat Q1 to hot body etself corning
back to its original state such that change in its internal energy is zero
i.p. ∆U=0
From I low ∆Q = ∆U+W
Q1-Q2 = 0+W=W
Coefficient of performance (COP)1
Q
Q2
T2
β= 2 =
=
W
Q1 -Q2
T1 -T2

Q1
T1 
Q Q = T 
2
2
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Relation in e and β. for an engine and a refrigerator working between the same temperature
corditors T1 & T2
Transmission of Heat :
From a higher temperature body to a lower temperature body. following three different modes of
heat from transmission
Conduction
Insolids
Convection
liquids
T1>T2
Radiation :
No medium is required
and gases
threngh EM
Envectaismrmts
are formed
from higher
Temperature
Body to lower
Temperature side
Heat passes in
solids is takes
place throngh
wibratory motais
of the solids.
heat passing
Depends
Change of weather
on (T1-T2), H, A,
t as follows
Q∝
A(T1 -T2 )t
x
Q=
KA(T1 -T2 )t
x
heating of liquid
aredents convection
Currents
radiation
of wavelength
range. 04 cm.
to . 85 mm.
there is no.
need of medium
ε = hV
ε=
he
λ
Energy from
sun to Earth is
in the form of
EM radiations
K → Coefficient of thermal conductmit of the material of heat conduetor
It =
KA(T1 -T2
Q
=
t
x
cal
sec
It → Theronal current.
K=
xQ
A(T1 -T2 )t
cal
m-k-sec
In steady state thermal current (It) become constant.
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e ≤ 1
e→
σ = 5.67 × 10 −8
emissimity of body
e= 1 for perfectly black body
W
σ→ 2 4
m -K
α → stefen’s constaint
Newtons law of cooling :
Rate of cooling of a body depeds on temperature diffence between the body and the
surrowding ie.
dT
∝ ( T-T0 )
dt
A → surface area of the body.
dT
= − bA ( T-T0 )
dt
b → constant.
b → depends on nature of the sugace invobred and the surramding conditions.
(-) sign indicates that for T>T0 temperature decraases with time.
Weins Displacement law :
I → intensity of emitted radiations
λ → warelength.
As temperature of radiating body inereases.
wavelength corresponding to which intensity of
emitted radiations is maximum decreases i.e.
1
λm ∝
T
λ mT = b
b → Meris constant
b = 2.88 x 10-3 m.k
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Magnetism Made Simple
Magnetism as a phenomenon has been udner study from time immemorial. The amount of
enthusiasm with which our ancestors have done experiment in this field, we are not able to do
and our younger lot is still deviating away. If one looks into the probable causes that led to
least interest being shown to this topic we are led to some points as below.
1.
Unable to correlate history of development of magnets with reality
2.
Not looking in to the molecular theory behind magnetism
3.
Not getting relevant instructions to master the directional natyure of field
4.
Inability of the reasoning to explain the earth's magnetism
5. Not allotting appropriate time for the learning and imparting of knowledge related to this
topic
6. Monotonous approach with only definitions, relations and formula substitution type
numerical questions
7.
Developing relations withthe topics already studied with Magnetism
In order to over-rule this type of problems, it is essential for us to change our Instruction
delivery approach and create some amount of understanding even at the molecular level.
In this article we are trying to provide some approaches and topics which may create interest
in this topic Magnetism.
1. Start with two or three experiments on magnetism which they have not seen earlier. For
example one can use some experiments as below :
(i)
To find the poles of a manget :
(a)
Fill the bowl or pie pan with water.
(b)
Place the magnet on top of the piece of wood and place them in the center of the
bowl of water.
(c)
Once the wood and magnet stop moving, check the direction the magnet is
pointing with your compass by placing in on the table next toyour bowl of water.
This tells you the direction of the North Pole and the South Pole.
(ii) At the bottom of a canyon, there is a big pile of gold bars that has been abandoned by
some robbers. How many do you think you can rescue?
How to Play : You will need to cut out 12 small rectangles of gold-coloured card, attach a
paper-clip to each of the gold bars, put them in an empty tissue box or shoe box. Each player
will need a pencil or a stick with a piece of string tied around the pencil or stick. Tie the other
end of the string around a magnet. The one who picks up the most gold bars with their fishing
magnet is the winner!
Magnets have a special power which enables them to attract things made from iron or
steel. One end of a magnet is called the north pole and the other end is called the south pole.
If you bring two north poles together they repel each other, or push each other away. But if you
put a south pole next to a north pole, they jump together because opposite poles attract.
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Give the students a feeling that Magnetism has revolutionized the modern Data storage system.
6.
Hysteresis loop -
Each atom of iron acts like a magnet, with its own north and south pole. In a domain the
atoms are arranged in an orderly fashion, so that they reinforce each other. The domain acts like a
magnet. But in un-magnetized soft iron the directions of magnetizations of groups of domains are
so arranged that their effective magnetization is zero o.e., net magnetic moment of the material is
µB=0. The effect of the current is to swivel round the domains so that they are all pointing in the
same direction. When they are all pointing in the same direction, no amount of current increase
can strengthen them any more. The iron bar is magnetically saturated. As the current is increased,
one domain after another swivels around. It is found that the amount of magnetization does not
increase smoothly (as indicated by the hysteresis loop), but in tiny steps as the direction of
magnetization of each domain swivels round into line. When the magnetic field suddenly changes
in this way, it causes an electromagnetic wave in the radio wave region of the spectrum. This
wave can be picked up, amplified, and turned into an audible sound. It is possible to actually listen
to the movement of the domains. Each domain movement is heard as a faint click. this is called
the Barkhausen effect.
Hysteresis is a measure of the work done or energy loss in one cycle of magnetization and
de-magnetisation per unit volume.
It is very imortnat here to observe the loop of iron and steel. It is highly a misguiding one as
people come to a conclusion that the retentivity should be less and the coercivity should be more
for making a permanent magnet. (Please use this graph to only compare steel and iron only.)
7.
At this stage one can introduce the relations pertaining to the estimate of magnetic
parameters along with their units. For example Susceptibility X, Intensity of Magnetisation I,
magnetization density M and Permeability µ etc.
8.
It will be appropriate to classify the materials into various classes based on their behaviour
in various circumstances.
Be Happy while doing Magnetism
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PROBLEM OF ABSENTEEISM
On the 31st of a month Pradeep Sharma, the teacher was finalizing his attendance for his
students. He could find that four studnets Neha Tyagi, Prashant Gupta, Parul Vaidya and
Gaurav Sinha were absent from the school twice a week in that month. He recalled that in the
previous month also they were absent for almost the same number of days. He discussed with
his colleagues, but could not find any reason for their absence. He was feeling a vaccum in the
class whenever they were absent. As a teacher he tried to find the problem and a possible
solution. Some of the thoughts that flowed in his mind are lsited here. It may be one or more of
the following points which must have led the students to stay away from the class.
1.
2.
3.
Neha Tyagi was nto healthy and having frequent fever.
Gaurav Sinha had his coaching class scheduled on the days of his absence.
Both Prashant Gupta and Parul Vaidya felt, it is not required to attent the classes in the
school as they have a tutor at home employed by their businessman father.
4. The students remained absent as on these days all the science teachers are not
expected in the school due to their own personal pre-occupation.
5. Parul always felt that self-study alone can make her to do well in the examinations.
6. Master Gupta is very sharp and finds the class very much slow and so does not want to
waste his time.
7. Gaurav Sinha does nto understand anything in the class as the teacher
(i)
does not lay stress on the understanding the concepts.
(ii)
does not encourage his/her students but scolds them for every small non-academic
issue.
(iii)
always writes on the board and expects the students to copy the same - irrespective
of the fact whether they do understand or not.
(iv)
never cracks jokes or sinks or mingles wiht their group.
(v)
is not good as per his standard.
(vi)
never dresses good and so his fellow friends pass unwanted comments which
distracts him in the class.
(vii) never appreciates the students on giving correct answers.
(viii) never permits the students to clear their doubts.
(ix)
feels offended if any student asks even genuine doubts and reduces their internal
marks.
(x)
wastes the class time by telling stories.
8. Gaurav feels that playing video games in the computer will not be possible after the
school hours as his working parents will be at home and will not permit the same for a
long period.
9. Neha is from a poor family whcih could not even afford two time meal. To support the
family she needs to work part-time which sometimes becomes full day. As a result she
misses her school.
10. Prashant Gupta wanted to take up his father's business after graduation and so is not
very keen on Science subject. He opted for science option as his close friends opted.
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In this scenario, as a teacher Mr. Pradeep Sharma is facing his class. The expert panel feels
that the following steps may be taken by the teacher.
The teacher should
1. Counsel the student about the various avenues available for each of the subjects - career
counseling.
2. Know the family background of each child and try to provide necessary emotional support
from time-to-time
3. Dress in a manner that the student feels that he is associated with a person of higher
status.
4. Start the classes always from the fundamentals - including the mathematical tools
necessary for the learning of Physics.
5. Never feel offended with the questions posed by the students, may be repeatedly.
6. Develop patience and expertise in his/her approach towards the problem of the students.
7. Build confidence in the students so that they feel that missing a class may bring a great
loss to them in the learning of the subject.
8. Solve certain questions which appeared in various competitive examinations as examples
based onthe CBSE course and make them feel that doing the course in the school
thoroughly will make them comfortable with any competitive examination.
9. Lay stress on the fact that continuity in learning will do wonders and so missing the class
for whatever the reason is tobe avoided.
10. Solving the problems in physics without knowing the fundamentals is no way help him in
clearing the IIT, AIIMS or any examination for entry into professional courses.
11. Use the time in the school in a productive way by solving the problems faced in various
subjects and/or trying to practice numerical solving.
12. Counsel them to do the best in whatever they attempt to do in life.
13. Insist on doing self-study in a planned way so that the short term and long term goals are
achieved with ease.
14. Provide incentive for regularity in learning by providing necessary books for reading at
home.
15. Use the time available in the school in a more productive way so that there exists a
feeling in the student's mind that he/she has done something that day.
16.
Encourage the low achievers even
when they answer a question partially and point even the smallest of the mistakes done
by the ability group.
More that the imparting of knowledge to the complete extent, if the teacher covers 80% and
allows the student to do the rest of the work, the student will be a complete learner. This goes
with the saying.
"Teachers do not teach the full but leave some for the students to learn" of the great
educationist Sir Rabindranath Tagore.
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HELP YOURSELF & YOUR STUDENTS VIA GOAL SETTING
Find Direction. Live Your Life Your Way
Goal setting is a powerful process for thinking about your ideal future, and for
motivating yourself to turn this vision of the future into reality. The process of setting goals
helps you choose where you want to go in life. By knowing precisely what you want to achieve,
you know where you have to concentrate your efforts. 'You'll also quickly spot the distractions
that would otherwise lure you from your course. More than this, properly-set goals can be
incredibly motivating, and as you get into the habit of setting and achieving goals, you'll find
that your self-confidence builds fast.'
Starting to Set Personal Goals
Goals are set on a number of different levels : First you create your "big picture" of
what you want to do with your life, and decide what large-scale goals you wat to achieve.
Second, you break these down into the smaller and smaller targets that you must hit so that
you reach your lifetime goals. Finally, once you have your plan, you start working to achieve it.
We start this process with your Lifetime Goals, and work down to the things you
can do today to start moving towards them.
SMART Goals :
A useful way of making goals more powerful is to use the SMART mnemonic.
While there are plenty of variants, SMART usually stands for :
•
S
Specific
•
M
Measurable
•
A
Attainable
•
R
Relevant
•
T
Time-bound
For example, insteadof having "to sail around the world" as a goal, it is more
powerful to say "To have completed my trip around the world by December 31, 2015."
Obviously, this will only be attainable if a lot of preparation has been completed beforehand!
Achieving Goals
When you have achieved a goal, take the time to enjoy the satisfaction of having
done so. Absorb the implications of the goal achievement, and observe the progress you have
made towards other goals. If the goal was a significant one, reward yourself appropriately. All
of this helps you build the self-confidence you deserve!
Key Points
Goal setting is an important method of :
•
Deciding what is important for you to achieve in your life.
•
Separating what is important from what is irrelevant, or a distraction.
•
Motivating yourself.
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•
Building your self-confidence, based on successful achievement of goals.
Five Principles of Goal setting
To motivate, goals must take into consideration the degree to which each of the
following exists :
1.
Clarity
2.
Challenge
3.
Commitment
4.
Feedback
5.
Tas complexity
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HOTS (Higher Order Thinking Skills) in Physics (Class XII)
The concept of HOTS introduced by CBSE in its class X and XII examinations, from the year
2008 is a fundamental concept of Education Reform, based on Bloom's Taxonomy. This
taxonomy lists the following six levels (in increasing order) in the hierarchy of cognitive
processing.
Knowledge, comprehension, Application, Analysis, Synthesis and Evaluation.
In the words of David. W. Dilliard, we may 'define' HOTS as follows :
Higher order thinking skills (HOTS) essentially mean that thinking that takes places in the higher
levels of hierarchy of cognitive processing and can be viewed as a continuum of thinking levels
starting with knowledge level thinking and moving eventually to evaluation level of thinking.
'HOTS' basically aims at developing and increasing cognitive development or critical thinking.
It aims at teaching students reasoning and processes - rather than teaching them simple
'recalling of facts' - and is expected to make them better life long learners. Its aim is not on
'drill' and repetition activities but on 'Problem Solving' and 'higher order thinking skills'. HOTS
thus moves away from simple general knowledge type skills to thinking skills like Synthesizing,
Analyzing, Reasoning, Comprehending, Application and Evaluation.
It is interesting to note that 'HOTS' questions are not necessarily 'difficult' questions. They
simply require the ability to relate knowledge from several areas, to use methods, concepts
and theories in new situations, to observe regularity and patterns and to organize the 'parts' of
a problem into a 'whole'. If done in a systematic, simple and interesting manner, 'HOTS' help in
developing better problem-solving abilities and doing critical thinking, analysis and evaluation.
It is interesting to note that research has indicated that even students, who are not good at
simply memorizing facts and figures, tend to benefit from learning and developing higher order
thinking skills that teach them the ways and techniques of solving problems.
The learning Research and Development Center (1991) has listed the following as higher
order thinking skills :
•
•
Size up and define a problem that is not neatly packaged.
Determine which facts and formulae, stored in memory, might be helpful for solving a
problem.
•
Carry out complex analysis or tasks that requrie planning management monitoring and
adjustements.
•
Recognize where more information is needed and where and how to look for it.
•
Step outside the 'routine' and deal with an unexpected breakdown or opportunity.
CBSE, from the year 2008, has moved away from simple, 'knowledge', 'understanding' and
'application' questions to questions that are data based or open ended or based on analysis
and interpretation of graphs or drawing graphs based on suitable mathematical results or
formulae or data or activity based or requrie sharp alternative thinking.
It is hoped that this new format of question framing will induce and encourage more and more
concept based teaching that will make students, 'better learners' and 'problem - solvers.'
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Q.3 A concave lens forms a real, erect and enlarged image of an object. What is nature,
position of the object. Draw an appropriate ray diagram.
Q.4 Two converging lenses L1 and L2 are mounted at the ends of a tube whose inner curved
surface has been painted black. The diameters of the two lenses equal the diameter of the
tube. Focal length of lens L1 and L2 is 2f and f respectively. The leses are so arranged that an
incident beam parallel to the axis of the tube on one lens emerges out as a parallel beam from
the other lens. A wide parallel beam is incident on L1 forming a bright What is illuminance spot
formed on the same screen as before?
Q.5
For some glass refractive index µ is
5.2 × 10
µ = 1.5020 +
λ2
_
15
Where λ is wave length of light in meter. A convex lens is made of above glass. Red
light (λ = 656 nm) is incident, as a parallel beam on the lens. The lens forms an image at a
distance of 12 cm. The incident red light is replaced by some monochromatic light of wave
length λ. The image formed by lens is nearer to lens by 23 mm. What is λ?
Q.6 A Plano convex lens is made of a material of dispersive power ω1. The radius of
curvature of curved surface of lens is C. The lens is placed in contact with an equi-concave
lens made of a material of dispersive power ω2. The combination is achromatic. Show that the
angular dispersion in the two lenses is in ratio of 2 : 1.
Q.7 Four immiscrible liquids having refractive indices in the ratio of 3 : 4 : 5 : 6 are poured to
same extent one over other in a beaker. What is the ratio of the equivalent refractive index of
the arrangement and the refractive index of first liquid?
Q.8 A bird flying at a height h above water in a pond views a fish in water at a depth d
below. The apparent depth of a fish as observed by bird is d1. The apparent height of the bird
as seen by the fish is h1. What is µ ?
Q9. In a young's double silt, the two interfering sources (regarded as point sources) are a
distance d apart. The interference fringes are observed on a screen at a distance D from the
interfering sources. What is maximum permissible width (w) of each source so that
interference fringes are observed?
Q.10
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A Plano - convex lens is placed on a plane glass plate XX' as shown. Mono-chromatic
parallel beam is incident as shown. Interference fringes are observed between light reflected
from the curved surface of lens and light reflected from plate XX'. Plate XX' is replaced by a
plane mirror without any other change. What change if any will be obsrved in the interference
fringes?
Photoelectric Effect
Q.1 A monochromatic point source λ = 600 nm is kept at a distance of 1m from a human
eye. The area of the pupil of eye is 40mm2. Estimate the numbr of phtons entering eye
in 1 second. Power of source is 40W.
Q.2. At what temperature the de Broglie wave length of
(i) a free electron in a metal
(ii) a helium atom
is 0.5 nm?
Q.3 Fig. shows the graph of photo-current vs applied p.d. v 1, v2 and v3 represent the
frequency of incident radiations in I, II and III. The corresponding values of intensity of
radiations are l1, l2 and l3. What is the relation if any between the frequency and intensity
in the three cases?
Q.4. A beam of total intensity 3.6 mW/m2 has three wavelengths 414.4nm; 497.2 nm; and
621.6 nm in it. The energy of incident beam is distributed uniformly amongst the three
wave lengths. The beam is incident on an area 10 2 mm2 of a clean metallic surface of
work function 2, 3 ev.
Assume there is no loss of energy of incident light and each incident photon ejects one
photoelectron. What is the total no. of photoelectrons emitted in two seconds?
Q.5 Radiations of frequency v (v > v0) are incident on a photosensitive material. The
stopping potential of emitted photoelectrons is Vs. The frequency of incident radiatiosn
is changed to 2v. Is the stopping potential of the emitted photoelectrons 2Vs?
Q.6 A metal plate is made of a material of work function 2eV. Light of  = 180 nm is incident
on the plate. A uniform magnetic field of 5×105 T is applied parallel to the plate. What is
the maximum radius of the path followed byt he photoelectrons emitted normally on the
plate?
Q.7 A metallic sphere is made of material having threshold wave length λ0. Monochromatic
radiation of wave length λ (λ > λ0) is incident on the sphere. How many photoelectrons
will be emitted before photoemission stops? Assume sphere is isolated.
Atoms and Nuclei
Q.1
A nucleus of mass number 200 initially at rest emits an α-particle. The Q-factor of
reaction is 5 MeV. What is the kinetic energy of emitted α -particle?
37
Q.2
Q.3
Q.4
Hydrogen atom in ground state is bombarded with a particle having energy (a) 8.0 eV
(b) 11.0 eV.
In each case how much energy is transferred to the hydrogen atom? Is collision elastic
or inelastic?
A hydrogen atom in its first excited state returns to ground state by emitting radiations of
wave length λ1. The wave length of emitted radiations is λ2. if it returns from 2nd excited
state to 1st excited state. What is the wave length of radiations emitted if it returns from
2nd excited state to ground state in one go?
The allowed energy states of some hypothetical atom is given by
k
eV
n2
Where k is a positive constant. In this atom photon of energy 2eV is emitted when
electron jumps from first excited state to ground state. What is energy of photon emitted
due to transition from second excited state to ground state? This photon is incident on a
photo sensitive material having work function of 1.07 eV. What is stopping potential of
emitted photoelectron?
A nucleus of 236Ra88 decays to 222Rn86 by the emission of an α-particle of energy 4.8
MeV. What is recoil energy of radon?
An electron is conferred to a hollow tube. The electron's potential energy in one half of
tube is zero, while in the other half it is 10eV. The total energy of electron in tube is
15eV. What is the ratio of the de Broglie wave length of the electron in the two halves of
the tube?
In hydrogen like atom 47.2 eV of energy is requried to excite electron from first excited
state to the next higher energy state. What is Z of the atom? What is kinetic energy,
potential energy and the angular momentum of the electron in the first permitted orbit?
Hydrogen atom in ground state is excited by monochromatic radiations of λ = 975 Å.
How many different lines are possible in the resulting spectrum?
A particle of mass m moves along a circular orbit in a central potential field
En =
Q.5
Q.6
Q.7
Q.8
Q.9
kr 2
2 , where k is a constant. Using Bohr's quantization condition calculate
(i)
radii of permitted orbits
(ii)
energy levels
Q.10 In a hydrogen like atom (Z=11) the electron undergoes a transition from nth state
emitting radiations corresponding to Lymann series. The wavelength of the emitted
radiations equals the de-Broglie wavelength of electron in nth orbit. What is n?
Q.11 A photon of energy 10.2 eV collides inelastically with a hydrogen atom in ground state.
After a few microseconds another photon of energy 16. oeV collides inelastically with
the same hydrogen atom. What is recorded in a suitably placed detector?
U(r) =
38
Career Opportunity in Physics (Soruce : www.cbse.nic.in)
Physics can be applied to many industries and engineering problems as the subject helps to
develop skills such as logical thinking, computing and problec solving, which are useful for any field
of work, or organization.
If you are an explorer, one who likes to see other parts of nature that few others have seen,
naturally like to take things apart, and spend time over details, these are good indicators for a
career in physics.
Good career opportunities for qualified physicists are available both as teachers and researchers.
For teaching jobs in universities and colleges, one has to qualify in the UGC -CSIR NET. Every year
a large number of candidates are recruited by several research institutions.
• Laboratory Assistant : This job revolves around taking care of the laboratory and its equipment.
The labassistant arranges instruments and apparatus foe various experiments to be conducted
in the lab. A PG Diploma in Medical Lab Technology would be better option though.
• Scientific Assistant : A scientific assistant works under a scientist and may have responsibilities
like recording routine readings of instruments, scanning books, internet and journals for
reference material, compiling working notes, itc.
• Forestry : Science graduates are eligible for the post of Forester and Forest Ranger. Candidates
qualifying in the written test and fulfilling prescribed physical requirements are sent to the Indian
Forest Research Institute and College at Dehradun or Coimbatore for a 2-year training course in
Forestry.
• Defence Services : Science graduates and postgraduates who meet the prescribed physical and
medical requirements and clear the entrance tests are eligible for appointment in the Indian
Army, Indian Navy and Air Force, and in the Defence Science Service.
• Other Entry Occupations : Physics graduates can always try for other options open to graduates
for all streams. These include various competitive exams, government jobs, subordinate
executive and clerical posts, etc.
• Sales : Science graduates are specially suited for sales f commercial products like
pharmaceuticals, scientific instruments, biotechnology products, etc. Medical representations
are hired by all pharmaceutical and medical equipment manufactures for promoting and
marketing their products to doctors and hospitals.
• Apprenticeship : Many industrial undertakings recruit science graduates for paid apprenticeship
in the chemical, mechanical, or other relevant engineering department. They are paid a stipend
during training and may afterwards be absorbed in the factories and laboratories.
• Management Trainees; On the basis of a selection test and interview, many business houses
employ promising science graduates as management trainees. On successful completion of
training, they are employed as executives.
A degree in Physics can start on a career in research and the building of knowledge in any
particular area of subject. Most students of physics work in research and development, enfineering,
and information technology fields. Some physicists work on problems at the frontier of knowledge,
in fields such as nuclear physics, astrophysics and so on. The main areas of research in physics
include astronomy and astrophysics, condensed matter physics and material science.
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