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India, Britain in education pledge

India’s Human Resources Minister Kapil Sibal began a high—level visit to Britain on Wednesday aimed at strengthening ties in the multi—billion pound education sector, officials said.

Kapil Sibal, Minister of Human Resource Development. File photo: Anu Pushkarna

Mr. Sibal will meet three cabinet ministers and discuss the broad range of cooperation between India and Britain under an education forum set up by the two countries.

The visit is set to be marked by the signing of a memorandum of understanding between British and Indian universities pledging to forge “more successful partnerships in higher education and research”, British officials said.

Mr. Sibal will give a keynote address to an audience including dozens of education ministers from around the world at a Learning and Technology World Forum.

He will also meet university vice-chancellors to set out his vision for the expansion of India’s education sector before signing a joint statement with Britisih Business Secretary Peter Mandelson.

“With almost 40 percent of India’s population under the age of 15, meeting India’s demand for education is among the foremost challenges for this new decade. I look forward to hearing Minister Sibal’s vision and hope that the UK can play a role in helping India to achieve its ambitions,” said Mr. Mandelson.

Britain, a world leader in education, views India as a major education market and is keen to not only attract more Indian students to cash—strapped British universities, but also help enter the market in India through collaborations.

More than 26,000 Indians are studying in Britain, according to British government figures — the fastest growing segment of foreign students.

The number of Indian students in Britain shot up a record 24 percent between 2005-06 and 2006-07 — from 19,205 to 23,835, according to the Higher Education Statistics Agency.

India is second among nations with the most students in British institutions. China tops the list, although the number of Chinese students fell from 50,755 to 49,595 over the same period.

Americans students rose eight percent to 15,955, putting the country third in the table.

Physics Mnemonics

Mnemonics are words that help in memorizing something.
Mnemonics may take the form of acronyms, phrases, songs , rhymes places or any word/words or sentences which are used in conversation or have popular appeal for easy remembrance and with which we can easily establish some association with the topic we want to memorize

 

Source: http://blogs.educationtimes.com/post/Physics-Mnemonics.aspx

1. CIVIL In Capacitor ( C) Current (I) leads Voltage (V)
In Inductor (L) Voltage (V) leads Current (I)
2 .Transformer Losses
Edison Electrified His Magic Filament Lamp
Eddy currents loss,Electrical (DC resistance of wires) loss, Hysterisis loss, Magnetic Flux Leakage loss
3.Energy Transferred = Potential difference x Charge
E T’s Phone Calls
4.ULTRAVIOLET (Ultraviolet , Visible and Infrared are in increasing order of wavelength: U,V and I are in the word Ultrviolet itself in that order)
5. Electromagnetic waves in order of increasing frequency
R I V U X Ga
Radio Waves ,Infra red, Visible , Ultraviolet ,X-rays, Gamma-rays
6. OHM’s LAW
VAMPIRES ARE RARE
Volts = Amperes x Resistance
7. Force (F) on a charge(Q) moving (v)perpendicular to a magnetic field
F = Q v B
Fast Quality Visualizes Business
8.Dia , Para and Ferromagnetic substances
DIAMAGNETIC:
Dial Straight To Wed Rupali
Explanation:
Diamagnetic Substances move from Stronger To Weeker part in a nonuniform magnetic field. Are repelled by magnets.
PARA & FERROMAGNETIC
Parth Wears T-Shirt Slowly but Ferro quickly. Both look attractive.
Explanation:
Paramagnetic substances move from Weeker To Stronger part in a nonuniform magnetic field slowly. Ferromagnetic do the same but quickly. Both are attracted by magnets.
9.Three Elements of Earths Magnetic Field
I Declined to take Horizontal Dip
Explanation:
Declination , Horizontal Component of Earth's Field, Dip or Inclination
10
. Colour Code for Resistances
B B R O Y of Great Britain had Very Good Wife
Black Brown Red Orange Yellow Green Blue Violet Grey White
0 1 2 3 4 5 6 7 8 9
11. Fleming's Left Hand Rule is for Motors
Fleming's Right Hand Rule is for Generators (Induction)
To remember read Generator as Genrighter
12. Units of Measurement
King Hector Died Mysteriously Drinking Choklate Milk
Kilo Hecto Deka Meter Deci Centi Milli
Tens ' Multipliers
Desi Hero Killed Mega Gigantic Terrorists
Dekka Hecto Kilo Mega Giga Tera
10E01 10E02 10E03 10E06 10E09 10E12
Fractional Multipliers
D C Millan May Not Play Football
Deci Centi Milli Micro Nano Pico Femto
10E-1 10E-2 10E-3 10E-6 10E-9 10E-12 10E-15
13. Galvanometer
Kafai is BINA

= BINA

K=Torsion constant of spring
¢ is deflection
B is Magnetic Field
I Current in Galvanometer coil
N no. of turns
A Area of coil

SCIENCE AND RELIGION

Religions rely on revelation,while science relies on observable,repeatable experiences in making statements about the world.
The relationship between religion and science can be of:-
1.Conflict - When either of them threatens to take over the legitimate concerns of the other.
2.Independence - Treating each as quite separate realms of enquiry.
3.Dialogue - Suggesting that each field has things to say to each other about phenomena in which their interests overlap.
4.Intergration - Aiming to unify both fields into a single discourse.
A modern view is that science and religion deal with fundamentally separate aspects of human experience and so,when each stays within its own domain they co-exist peacefully.
          Science is concerning 'what is' while religion is concerning 'what should be'.The facts and relationships between facts are revealed by science while value judgements are given by religion.We need both.
View of Albert Einstein
              "My religion consists of a humble admiration of the illimitable superior spirit who reveals himself in the slight details we are able to perceive with our frail and feeble minds.That deeply emotional conviction of the presence of  a superior reasoning power,which is revealed in the incomprehensible universe,forms my idea of God".
     [ cited in Lincoln Barnett ,The Universe and Dr. Einstein(The new American Library,New York.1964) pp.108-109 ]

   Jofred Joseph

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ISC Physics Sample Paper 2010

PHYSICS
Paper – 1
(THEORY)
(Three hours)
(Candidates are allowed additional 15 minutes for only reading the paper.
They must NOT start writing during this time)
----------------------------------------------------


Answer all questions in Part I and six questions from Part II, choosing two questions from each of the Sections A, B and C.
All working, including rough work, should be done on the same sheet as, and adjacent to, the rest of the answer.
The intended marks for questions or parts of questions are given in brackets [ ].
(Material to be supplied: Log tables including Trigonometric functions)
A list of useful physical constants is given at the end of this paper.

-----------------------------------------------------------------------
PART I
Answer all questions
Question 1 [5]

A. Answer all questions by choosing the correct option A, B, C or D.
(i) Three identical point charges, each of Q Coulomb, are kept at the three vertices of an equilateral triangle having each side = a. [See figure 1]. Electro-static potential energy of the system is:

pic1

(ii) Four cells E1 , E2 , E3 and E4 are connected as shown in Figure 2. Emf of the battery so formed is:

pic2

(iii) A 50 Ω non-inductive resistor is connected to a source which generates an emf e which is given by
e = 200 Sin (120 π t) Volt. Peak value of current flowing through the resistor is:
(A) 0.25 A (B) 2.5 A (C) 4.0 A (D) 42 A
(iv) A thin converging lens of focal length 25 cm is kept in contact with a thin diverging lens of focal length 20 cm. Focal length of the combination is:
(A) + 100 cm (B) -100 cm (C) 45 cm (D) 5 cm
(v) Photo electric threshold wavelength of a certain metal is 198 nm. Its work function is:
image

B. Answer all questions briefly and to the point: [15]
(i) An oil drop weighing 1 × 10-15 N and carrying a charge of 8 × 10-19 C is found to remain at rest in a uniform electric field of intensity ‘E’. Find ‘E’.
(ii) Which conservation principle is involved in Kirchoff’s second law?
(iii) State any one difference between Joule effect and Peltier’s effect.
(iv) Two thin, infinitely long conductors, X and Y, carrying currents I1 and I2 are kept parallel to each other, at a distance ‘a’, in vacuum [See figure 3].

pic3

How much force acts on a 1m span of wire Y due to current flowing through X?
(v) Alternating current I flowing through a device lags behind the potential difference V across it by 90° or 2π radian. Is this electrical device a resistor, an inductor or a capacitor?
(vi) An electro magnetic wave has a frequency of 1 MHz. On which part of the electro magnetic spectrum does this wave lie?
(vii) What kind of source produces a cylindrical wave front?
(viii) Plot a labelled graph showing variation of relative intensity with respect to distance, in a single slit diffraction experiment.
(ix) State any one method by which chromatic aberration produced by a convex lens can be minimized.
(x) Give any one reason why giant telescopes all over the world are of reflecting type.
(xi) Figure 4 below is a graph showing variation of relative intensity I of X rays Vs its wavelength λ , when X ray tube is operated at a tube potential of 20 KV.

pic4

Redraw this graph in your answer book and on same axes, draw another such graph when tube potential is raised to 30 KV.

(xii) Write down the relation between mean life τ of a radioactive substance and its half life T½ .
(xiii) According to the modern view, matter and energy are inter-convertible. Give one example where energy is converted to matter.
(xvi) Draw graphs to show input and output voltages of an ideal amplifier.
(xv) Write down the truth table of a NAND gate.

PART II
Answer six questions in this part, choosing two questions
from each of the Sections A, B and C.
SECTION A
(Answer any two questions)

Question2
(a)Figure 5 (a) below shows a parallel plate air capacitor whose capacitance is 2μF.  4]

pic5

A dielectric slab MN of thickness t = 2 cm andhaving dielectric constant (relative permittivity) = 10 is now introduced between the two plates (See figure 5 (b))
Find the new capacitance of the system. [4]
(b) Using Gauss’ Theorem, calculate intensity of electric field at a point at a radial distance of 3 cm from an infinite line charge having linear charge density of 5 × 10-6Cm-1.
(Statement of Gauss’ Theorem or derivation not required). [2]
(c) What is meant by temperature coefficient of resistance? Write down Ohm’s Lawin vector form, stating the meaning of every symbol used. [3]

Question 3
(a) Draw a labelled diagram of a balanced Wheat Stone bridge. Using either Ohm’s Law or Kirchoffs’ Laws, obtain the relation between four resistors forming the bridge.[3]
(b)Figure 6 below shows a potentiometer circuit. When the jockey is pressed on the slide wire AB at a point C such that AC = 2.9m, the galvanometer ‘G’ shows no deflection. Find the emf of the cell X.    [3]

pic6

(c)Figure 7 below shows three resistors: R1 = 10Ω , R2 = 20Ω and R3 = 90Ω. When a current I enters the circuit, heating power developed in R1is found to be 90 W. Calculate the heating power developed in R3 .

image

Question 4
(a) Using Ampere’s circuital law, obtain an expression for magnetic flux density ‘B’ at a point ‘P’near an infinitely long straight conductor carrying a current ‘I’. [3]
(b) Show graphically how a d.c current flowing through an LR circuit varies with time when the key is put (i) on (ii) off. What is meant by time constant of an LR circuit ? [3]
(c) A 225()Fμπcapacitor ‘C’ and a 50 Ωresistor ‘R’ are connected in series to a 220V, 50Hz a.c supply. It is desired to have a current of 2A in phase with supply voltage. Find the value/s of additional component/s to be connected in series with C and R. [3]


SECTION B
(Answer any two questions)

Question 5
(a) Which electro-magnetic wave is longer than a light wave but shorter than a micro-wave? How can it be detected? Name only one detector. [2]
(b) In Young’s double slit experiment, what is the effect of the following changes on the interference pattern:
(i) Distance between the two slits is decreased.
(ii) One of the slits is covered with a thin mica sheet.
(iii) Monochromatic light is replaced by white light. [3]
(c) Ordinary light i.e. unpolarized light is incident on a glass slab (refractive index = 1.6) at a polarizing angle θp as shown in figure 8 below.

image

(i) Find the value of angle θp.
(ii) What is the angle between the reflected ray R1 and the refracted ray R2 ?
(iii) What is the difference between the incident light and the reflected light, as far as their electric vectors are concerned?

Question 6
(a) An air bubble ‘A’ is trapped inside a glass sphere of radius CP = 10 cm at a distance of 4.0 cm from its centre ‘C’. Where does it appear to an observer O (See figure 9) who is looking at it along the diameter from the side to which it is nearest?
(Refractive Index of glass = 1.5)

image

(b) A beam of light converges to a point X. A convex lens of focal length 30 cm is now introduced in its path in order to intercept the rays, at a distance of 30 cm from X. The rays of light now meet at a point Y. Draw the ray diagram showing the position of X & Y and calculate the distance XY. [3]
(c)What are Fraunhoffer lines? Explain how they are formed. [2]
Question 7
(a) Explain the statement: “Angular magnification of an astronomical telescope in normal adjustment is 20”. What is meant by resolving power of a telescope? [3]
(b)Draw a labelled ray diagram of an image formed by a Compound Microscope in normal use. Write down an expression for its magnifying power in terms of focal lengths of the two lenses used. [3]
(c) When a narrow and parallel beam of monochromatic light is incident normally on a rectangular slit of width 1 × 10-6m, angular width of central maxima in the diffracted light was found to be 60°. Find the wave length of the incident light. [2]

SECTION C
(Answer any two questions from the following)

Question 8
(a) In Millikan’s oil drop experiment, charge q on an oil drop is given by 112Kq=V (V-V)E.
(i) What is the difference between V1 and V2?
(ii) What is meant by the term: “Quantisation of charge”? [3]
(b) When UV radiation of wavelength 198.0 nm is incident on a Caesium photo cell, a negative potential difference of 4.2V has tobe applied to just cut off the photo-current. Calculate threshold frequency for metal Caesium. [3]
(c) (i) Find angular momentum of an electron in Bohr’s III orbit.
(ii) What is the radius of IIIrd orbit of an electron in hydrogen atom? [2]
Question 9
(a) Explain the terms:
(i) Mass defect.
(ii) Binding energy of a nucleus. [2]
(b) (i) In Nuclear Physics, what is the use of a cyclotron ?
(ii) In a nuclear reactor, what is the function of a moderator ? [2]
(c) (i) State Mosley’s Law.
(ii) What is a neutrino?
(iii) Half life of a certain radio active element is 6 hours. If you start with 32g of this element, how much of it would disintegrate in one day? [4]

Question 10
(a) Draw labelled energy band diagram for each of the following:
(i) A semi-conductor.
(ii) An insulator.
(iii) A good conductor. [3]
(b) Draw a labelled circuit diagram of a full wave rectifier using two junction diodes. You must show clearly where input voltage is applied and where output voltage is taken. [3]
(c) Show how an OR gate can be obtained using NAND gates. [2]
image

ISC Board 12th Exam Date Sheet 2010 | ISC Board Class XII Time table

To be Published soon

ICSE Board 10th Exam Date Sheet 2010 | ICSE Board Class X Time table

Council for the Indian School Certifcate Examinations (CISCE)will be announcing the time table for ICSE 2010  soon. We will make the date sheet as soon as it is published.

Come back soon ………………….

Chat brain-to-brain at the speed of thought Future Of The Web? Thoughts, Images Can Be Transmitted To Minds Without Using An Interface

London: Ever wanted to communicate your thoughts without speaking a word? British scientists have created a system for “brain to brain communication”, a development researchers claimed will allow people to send thoughts, words and images directly to the minds of others.
    The system, developed by the researchers at the British University of Southampton, has been hailed as the future of the internet, which would provide a revolutionary way to communicate without the need for keyboards and telephones.
    It was claimed the technology, the first of its kind, would allow people to send thoughts, words and images directly to the minds of others, particularly people with a disability.
    “This could be useful for those people who are locked into their bodies, who can’t speak, can’t even blink,” said the lead scientist Christopher James.
    However, he cautioned that his experiments were “the first baby steps” towards technologies that would allow people instantly to send thoughts, words, and images directly into the minds of others.
    Scientists used “brain-computer interfacing”, a technique that allows computers to analyse brain signals, that enabled them to send messages formed by a person’s brain signals though an internet connection to another person’s brain miles away.
    According to James, during transmission two people were connected to electrodes that measure activity in specific parts of the brain. The first person generated a series of zeros and ones, where they imagined moving their left arm for zero and right arm for one.
    After the first person’s computer recognises the binary thoughts, it sends them to the internet and then to the other person’s computer.
    A lamp is then flashed at two different frequencies for one and zero. “It’s not telepathy,” James said. e added: “There’s no conscious thought forming in one person’s head and another conscious thought appearing in another person’s mind.
    “The next experiments are to get that second person to be aware of the information that is being sent to them. For that, I need to get my thinking cap on, so to speak.” AGENCIES

PHYSICS PROBLEM SOLVING STRATEGY

PHYSICS PROBLEM SOLVING STRATEGY

Dr. Mark Hollabaugh

Normandale Community College

Two factors can help make you a better physics problem solver. First of all, you must know and understand the principles of physics. Secondly, you must have a strategy for applying these principles to new situations in which physics can be helpful. We call these situations problems. Many students say, “I understand the material, I just can’t do the problems.” If this is true of you as a physics student, then maybe you need to develop your problem-solving skills. Having a strategy to organize those skills can help you.

Physics problem solving can be learned just like you learned to drive a car, play a musical instrument, or ride a bike. What can aid you more than anything is to have a general approach to follow with each problem you encounter. You may use different tools or tactics with differing areas of physics, but the overall strategy remains the same. Most likely, you have already acquired some problem-solving skills and habits from previous courses in physics, chemistry, or mathematics. Like other areas of learning and life, some of these habits may be beneficial and some may actually hinder your progress in learning how to solve physics problems.

So, in learning this new approach, be willing to try new ideas and to discard old habits that may in fact be hindering your understanding. As you mature as a physics problem solver, you will find that the approach will become second nature to you. You will begin automatically to do those things that will lead you to construct an effective solution to the problem.

As with so many other learning activities, it is useful to break a problem solving strategy into major and minor steps. The strategy we would like you to learn has five major steps: Focus the Problem, Physics Description, Plan a Solution, Execute the Plan, and Evaluate the Solution. Let’s take a detailed look at each of these steps and then do an sample problem following the strategy. At this stage of our discussion, do not worry if there are physics terms or concepts that you do not understand. You will learn these concepts as they are needed. Then, refer back to this discussion.

Click Here to Read More

BERNOULLI’s PRINCIPLE

In fluid dynamics, Bernoulli's principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. Bernoulli's principle is named after the Dutch-Swiss mathematician Daniel Bernoulli who published his principle in his book Hydrodynamica in 1738.

clip_image002

Bernoulli's principle can be applied to various types of fluid flow, resulting in what is loosely denoted as Bernoulli's equation. In fact, there are different forms of the Bernoulli equation for different types of flow. The simple form of Bernoulli's principle is valid for incompressible flows (e.g. most liquid flows) and also for compressible flows (e.g. gases) moving at low Mach numbers. More advanced forms may in some cases be applied to compressible flows at higher Mach numbers.

Bernoulli's principle can be derived from the principle of conservation of energy. This states that in a steady flow the sum of all forms of mechanical energy in a fluid along a streamline is the same at all points on that streamline. This requires that the sum of kinetic energy and potential energy remain constant. If the fluid is flowing out of a reservoir the sum of all forms of energy is the same on all streamlines because in a reservoir the energy per unit mass (the sum of pressure and gravitational potential ρ g h) is the same everywhere.

Fluid particles are subject only to pressure and their own weight. If a fluid is flowing horizontally and along a section of a streamline, where the speed increases it can only be because the fluid on that section has moved from a region of higher pressure to a region of lower pressure; and if its speed decreases, it can only be because it has moved from a region of lower pressure to a region of higher pressure. Consequently, within a fluid flowing horizontally, the highest speed occurs where the pressure is lowest, and the lowest speed occurs where the pressure is highest.

APPLICATIONS OF BERNOULLI’s PRINCIPLE

1. The carburetor used in many reciprocating engines contains a venturi to create a region of low pressure to draw fuel into the carburetor and mix it thoroughly with the incoming air. The low pressure in the throat of a venturi can be explained by Bernoulli's principle; in the narrow throat, the air is moving at its fastest speed and therefore it is at its lowest pressure.

A carburetor is a device that blends air and fuel for an internal combustion engine. It was invented by Karl Benz before 1885 and patented in 1886. It is colloquially called a carb. The word carburetor comes from the French carbure meaning "carbide". Carburer means to combine with carbon. In fuel chemistry, the term has the more specific meaning of increasing the carbon (and therefore energy) content of a fuel by mixing it with a volatile hydrocarbon.

clip_image004

2. The Pitot tube and static port on an aircraft are used to determine the airspeed of the aircraft. These two devices are connected to the airspeed indicator which determines the dynamic pressure of the airflow past the aircraft. Dynamic pressure is the difference between stagnation pressure and static pressure. Bernoulli's principle is used to calibrate the airspeed indicator so that it displays the indicated airspeed appropriate to the dynamic pressure.

A pitot tube is a pressure measurement instrument used to measure fluid flow velocity. The pitot tube was invented by the French engineer Henri Pitot in the early 1700s and was modified to its modern form in the mid 1800s by French scientist Henry Darcy. It is widely used to determine the airspeed of an aircraft and to measure air and gas velocities in industrial applications.

The basic pitot tube consists of a tube pointing directly into the fluid flow. As this tube contains fluid, a pressure can be measured; the moving fluid is brought to rest (stagnates) as there is no outlet to allow flow to continue. This pressure is the stagnation pressure of the fluid, also known as the total pressure or (particularly in aviation) the pitot pressure.

The measured stagnation pressure cannot of itself be used to determine the fluid velocity (airspeed in aviation). However, Bernoulli's equation states:

Stagnation Pressure = Static Pressure + Dynamic Pressure

Which can also be written

clip_image005

Solving that for velocity we get:

clip_image006

Where V is fluid velocity

and pt is stagnation or total pressure

and ps is static pressure

and ρ is fluid density

The dynamic pressure, then, is the difference between the stagnation pressure and the static pressure. The static pressure is generally measured using the static ports on the side of the fuselage. The dynamic pressure is then determined using a diaphragm inside an enclosed container. If the air on one side of the diaphragm is at the static pressure, and the other at the stagnation pressure, then the deflection of the diaphragm is proportional to the dynamic pressure, which can then be used to determine the indicated airspeed of the aircraft. The diaphragm arrangement is typically contained within the airspeed indicator, which converts the dynamic pressure to an airspeed reading by means of mechanical levers.

Instead of static ports, a pitot-static tube may be employed, which has a second tube coaxial with the pitot tube with holes on the sides, outside the direct airflow, to measure the static pressure.

Pitot tubes on aircraft commonly have heating elements called pitot heat to prevent the tube from becoming clogged with ice. The failure of these systems can have catastrophic consequences, as in the case of Austral Líneas Aéreas Flight 2553, Birgenair Flight 301 (investigators suspected that some kind of insect could have created a nest inside the pitot tube. The prime suspect is a species called the Black and yellow mud dauber wasp), Northwest Orient Airlines Flight 6231, AeroPeru Flight 603 (blocked static port), and of one X-31.

clip_image008clip_image010

class 11 second terminal examination physics

  1. What do you mean by systematic error ?
  2. Each side of a cube is measured to be 7.023m.  What is the total surface area of the cube to appropriate significant figures ?
  3. State work-energy theorem.
  4. Find the vector product of two vectors a=( 3i^-4j^+5k^) and  b =(-2i^ + j^-3k^)
  5. Define universal gravitational constant.
  6. State Newton's 2nd law of motion and explain force from it
  7. Show the range of a projectile is maximum when θ=45
  8. Io one of the satellite of Jupiter,has an orbital period of 1.769 days and radius of orbit is 4.22 x 10 8 m . Show that mass of Jupiter is about one-thousandth that of the sun.
  9. What is the moment of inertia of a rod of mass M, length l about an axis perpendicular to is through one end. Given moment of inertia about its own axis is Ml2 /12.
  10. Find the angle force F=(3i^+4j^-5k^) unit and displacement d=(5i^+4j^-3k^ ) unit.Also find the projection of F on d.
  11. Derive an expression for potential energy of a spring
  12. How will you find the centre of mass of triangular lamina ?
  13. State Kepler’s law of planetary motion
  14. Derive an expression for the relation between torque and angular momentum of rotation about a fixed axis.
  15. Differentiate translational motion and rotational motion.
  16. Derive an expression for  linear velocity and angular velocity of v and w.
  17. Find the torque of a force 7i^ +3j^-5k^about the origin. the force acts on the particle whose position vector is i^-j^+k^.
  18. A 1kg block is situated on a rough inclined is connected to a spring of spring constant 100 Nm-1 as shown in fig. The block is released   from rest with the spring in the unstretched position.The block moves 10 cm down the incline before coming to rest. Find the coefficient of friction between the black and the incline .Assume that the spring has negligible  mass and the pulley is frictionless.
  19. Derive an expression for orbital velocity and time period of a satellite
  20. A rocket is fired vertically from the surface of mars with speed of 2km/s. If 20% of its initial energy is lost due to Martian atmospheric resistance , how far will the rocket go from surface or mars before returning to it ? Mass of mars =6.4x10 23 kg , radius of mars =3395 km ,G = 6.67x10 11 Nm2kg-2.
  21. State and explain law of conservation of energy in the case of a freely falling body.
  22. State and explain the laws of (a) kinetic energy (b) static friction.
  23. Derive an expression for acceleration due to gravity with respect to (a) variation with altitude ‘h’  (b) variation with depth ‘h’
  24. State law of conservation of angular momentum  for a rotating body.
  25. Briefly describe an elastic collision in one dimension and find the relation between initial and final velocities before and after collision and discuss the following cases.   (a)The masses of colliding bodies are equal.  (b) The target body is initially at rest.
  26. A rear side of a truck is open and a box of 40 kg mass is placed 5km away from the open end as shown in fig.the co-efficient of friction between the box and the surface below it is 0.15 . On a straight road the truck starts from rest and accelerates with 2m/s 2. At what distance from the starting point does the box fall off the truck ? Ignore the size of the box.
  27. a. State perpendicular axis  theorem and parallel axis theorem.   b .Derive an expression for moment of inertia of a ring about its diameter. c.The oxygen molecule has a mass of 5.30 x10 –26 kg and a moment of inertia of 1.94 x10 –46 kgm 2 about an axis through its centre , perpendicular to the line joining the two atoms. Suppose the mean speed of such a molecule in gas is 500 m/s and that its kinetic energy of rotation is two thirds of its kinetic energy of translation.Find the average angular velocity of the molecule.
  28.  

A Guess Paper in Physics for ICSE Physics

Physics
·         Answers to this Paper must be written on the paper provided separately. 
·         You will not be allowed to write during the first 15 minutes. 
·         This time is to be spent in reading the Question Paper. 
·         The time given at the head of this Paper is the time allowed for writing the answers.
·         Section I is compulsory. Attempt any four questions from Section II
·         The intended marks for questions or the parts of questions given in brackets [ ].
SECTION I (40 Marks)  Attempt all questions from this Section
Question 1 If ‘m’ is the mass of the body, ‘v’ its velocity and ‘p’ the momentum then write a relationship between change in momentum , mass and velocity of the body when :
(i)             v is almost equal to c ,the velocity of light ;
(ii)            v is very-very less as compared to c ,the velocity of light.  (2)
 (b) Diagram alongside shows a weightless lever in equilibrium. Neglect friction at the fulcrum F.
  1. State the principle of moments as applied to the alongside lever.
  2. Define mechanical advantage and calculate its value for the given lever.
  3. Name the type of lever which has mechanical advantage greater than 1.(1+2+1)
(c) When an arrow is shot from a bow, it has kinetic energy in it. Explain briefly from where does it get its kinetic energy?. [2] (d) What energy conversions take place in the following when they are working- (i) Electric toaster (ii) Microphone?. [2] 
Question 2(a) (i) A monochromatic beam of light of wavelength λ passes from air into a glass block. Write an expression to show the relation between the speed of light in air and the speed of light in glass. (ii) As the ray of light passes from air to glass, state how the wavelength of light changes. Does it increase, decrease or remain constant? (1+1)
 (b) An object is placed in front of a converging lens at a distance greater than twice the focal length of the lens. Draw a ray diagram to show the formation of the image. [2]
(c) Mention one difference between reflection of light from a plane mirror and total internal reflection of light from a prism. [2]
(d) The V-I graph for a series combination and for a parallel combination of two resistors is as shown in the figure below:-
Which of the two, A or B, represents the parallel combination? Give a reason for your answer. [2]
(e) Of the three connecting wires in a household circuit:- [2]
  1. Which two of the three wires are at the same potential?
  2. In which of the three wires should the switch be connected?
Question 3 (a) The diagram given below shows a right-angled prism with a ray of light incident on the side AB. (The critical angle for glass is 420) [3]
  1. Copy the diagram and complete the path of the ray of light in and out of the glass prism.
  2. What is the value of the angle of deviation shown by the ray?
(b) (i) A particular type of high energy invisible electromagnetic rays help us to study the structure of crystals. Name these rays and give another important use of these rays.
(ii) How does the speed of light in glass change on increasing the wavelength of light? [4]
(c) (i) With the help of a well-labelled diagram show that an apparent depth of an object, such as a coin, in water is less than its real depth.
(ii) How is the refractive index of water related to the real depth and the apparent depth of a column of water? [3]
Question 4(a) [1+2]
  1. State Ohm's law.
  2. State the factors that alter the resistance af a conductor.
(b) The alongside circuit diagram shows three resistance 2Ω, 4Ω and RΩ connected to a battery of emf 2V and internal resistance 3Ω. A main current of 0.25A flows through the circuit: [5]
  1. What is the P.D., across the 4Ω RΩ AΩ resistor?
  2. Calculate the PD., across the internal resistance of the cell.
  3. What is the PD., across the RΩ or the 29 resistors?
  4. Calculate the value of R.
(a)   State two ways of increasing the speed of rotation of a D.C. motor. [2]
SECTION II (40 Marks) Attempt any four questions from this Section
Question 5(a) (i) A stone of mass 64.0 g is thrown vertically upward from the ground with an initial speed 20.0 m/s. The gravitational potential energy at the ground level is considered be zero. Apply the principle of conservation energy and calculate the potential energy at the maximum height attained by the stone. (g = 10 m s-2) . [3] (ii) Using the same principle, state what will be the total energy of the body at its half-way point?
 (b) Define 'joule', the SI unit of work and establish relationship between the SI and CGS unit of work . [3]
 (c) (i) Draw a labelled diagram of a block and tackle system of pulleys with two pulleys in each block. Indicate the directions of the load, and effort and tension in the string. [4] (ii) Write down the relation between load and the effort of the pulley system.
Question 6(a) Explain, why bottled soft drinks are more effectively cooled by cubes of ice than by ice water? [5]
(b)10 g of ice at 00C absorbed 5,460 J of heat to melt and change into water at 500C. Calculate the specific latent heat of fusion of ice. [Specific heat capacity of water is 4,200 J/kg/0C]. [4]
(c) In an experiment to determine the specific latent heat of vaporisation af steam L, the following measurements were taken. Mass of calorimeter + stirrer = x kg. Mass of water = y kg. Initial temperature of water = t01,°C Final temperature of mixture = t2°C [Given : S.H.C., of calorimeter and water are S1 and S2 respectively]. Express in terms of above data. [4]
Question 7(a) [6]
  1. State any two characteristics of a wave motion.
  2. What is the relation between frequency, wavelength and speed of a wave?
  3. A longitudinal wave of wavelength l cm travels in air with a speed of 330 m/s. Calculate the frequency of the wave. Can this wave be heard by a normal human being?
(b) Two waves A and B have wavelengths 0·01 Å and 9000 Å respectively. [4]
  1. Name the two waves.
  2. Are the speeds of these two waves equal when they travel in vacuum?
  3. If the amplitude of a wave is doubled what will be the effect on its loudness?
Question 8(a) Given alongside is the circuit diagram in which three resistances 1Ω, 2Ω and 3Ω are connected to a cell of emf 2 V and internal resistance 0.5Ω. [6]
  1. Calculate the total resistance of the circuit.
  2. What is the reading of the ammeter?
  3. What will be the ammeter reading if an exactly similar cell is connected in series with the given cell? (b) [4]
  1. Draw a neat labelled diagram of an a.c.generator.
  2. What is the magnitude of the emf induced in the coil when its plane becomes parallel to the magnetic held?
Question 9 (a) The following diagram is the simplified version of an electrode gun which is an integral part of a cathode ray-tube. 'A' is a metal cylinder. [5]
  1. Copy the diagram in your answer book. Draw a pair of planets P1 and P2 to apply electric field, a screen S and an enclosure.
  2. What are the functions of A, B, P1 and P2.
(b) 27 Mg β Al Y       12 -->    -->
In the above nuclear reaction. [3]
  1. 27Mg12 emits α, β-particle and is transformed to aluminium. What is the mass number and the atomic number of aluminium.
  2. Aluminium emits γ ray. What is the resulting nucleus?
(c) [2] 1)Which radiation or particle from radioactivity produces maximum biological damage? 2)State three precautions that must be taken while handling a radio active source.
Question 10(a) A block of mass 30 kg is pulled up a slope (diagram alongside) with a constant speed by applying a force of 200 N parallel to the slope. A and B are initial and final positions of the block. [4]
  1. Calculate the work done by the force in moving the block from A to B.
  2. Calculate the potential energy by the block.
(b) Diagram alongside gives an arrangement of single moving pulleys. Copy the diagram If the effort applied at the free end of the string is E, [3]
          i.        Show the direction and magnitude of the forces exerted by the four strings marked (1) to (4).
         ii.        What is the load which can be lifted by the effort?
iii.        Calculate the mechanical advantage of the system of pulleys.
(a)   [3] i)State the equation for the relation between the frequency and wave length of light in vacuum. ii)What is the relation between the angle of incidence 'i' in the liquid and the angle of refraction 'r' in the glass?

Physics – ICSE Board Previous Question Paper

SECTION -I
COMPULSORY : To be attempted by all candidates.

Q 1 (a)(i)How fast should a man weighing 60 Kg run so that his Kinetic energy is 750 J?

(ii) A body of mass 1 Kg is thrown vertically up with an initial sped of 5 m/s. What is the magnitude and direction of force due to gravity acting on the body when it is at its highest point?

Q 1 (b)Diagram given below shows a weightless lever in equillibrium. Neglect friction at the fulcrum F.

(i) State the principle of moments as applied to the above lever.

(ii) Define mechanical advantage and calculate its value for the given lever.

(iii) Name the type of lever which has mechanical advantage greater than 1.


Useful Books in Physics

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