Physics Board Revision for Std. XII By : Dr. Nitin Oke Safe Hands, Akola

Note these General and essential Points - - - It is essential to give question number and sub question number in the margin provided. Next question ( NOT SUBQUESTION) must start on next page. Draw relevant diagrams even if not asked. All figures must be drawn by pencil. They must be labeled and sufficiently large. Safe Hands

Note these Points - - - Safe Hands While solving numerical problems first write given data convert it into S.I. units. Write the formula needed and substitute the values. Do calculations using log or direct in a box call it as rough work ( it should be neat and good looking) The answer of numerical problem must be with units and should be in a box. While deriving any expression remember that your next step is outcome of previous step. If you want to cancel some part don’t cancel it as “Parallel axis theorem : If Iz is MI about an axis perpendicular it should be as— Safe Hands

Points you need to remember Diagrams must be labeled and arrow must be shown for current and vectors. The key must be introduced and polarities of A, V, source, must be shown. Show polarity of cells Arrow on wire indicating direction of current Remember to show variable resistance (rheostat), key, Galvanometer, source of e.m.f. with polarity ( take proper care when used in potentiometer) All most every definition must be with example. If question is about comparison or assumptions then just give the list of points. Safe Hands

Points to remember Safe Hands While doing numerical problems of meter bridge or Whetstone's network better have figure. When ac is applied direction of current is not to be showed Remember to indicate transformer, primary, secondary, load resistance, “e” input ac voltage, Vo output voltage, if full wave rectifier then center tap, direction of current in load resistance connected to output. Once you note down data in SI units think about formula needed and use it . Safe Hands

PAPER “Physics” BOARD PATERN IS Single Paper of 3 hours with total marks 70 =35 ( section I ) + 35 (Section II) Passing will be at 18 ( Useful for NEET students) QU1 : ( 7 marks) one will be numerical QU2 :( 12 marks) 2 marks each solve any 6 /8 (at least 4 numerical problems) QU 3:( 9 marks) 3 marks each solve any 3 from 4 (at least 1 numerical problems) QU 4: (7 marks) 7 marks each solve any 1 from 2 (subpart with at least 2 or 3 numerical problems) Safe Hands

IN SHORT IN PHYSICS PAPER WILL CONSIST OF 12 MCQ based on theory 2 MCQ based on numerical in all 14 MCQ 16 short answer questions of 2 marks each with 8 numerical from which you need to solve 12 means 12 short answer questions Two 3 marks and 1 four mark question with less choice 2 from QU 3 and 1 from QU 4. with 3 numerical of 3+ 4 or 3 marks. Means in Paper of Physics 25 marks will be numerical Safe Hands

Total Marks 4/5 Question may be of 1,2,3 or 4 marks Circular Motion Total Marks 4/5 Question may be of 1,2,3 or 4 marks Safe Hands

Circular Motion Safe Hands Questions for 2 marks Define uniform circular motion. Why it is called as periodic? Define angular displacement, radius vector Define angular acceleration, Centripetal force Obtain relation between velocity and angular velocity of a particle in UCM Obtain relation between linear acceleration and angular acceleration of a particle in circular motion Safe Hands

What is banking of road?Is the safe speed limit is same for all vehicles? why? Derive expression for maximum speed where the curved road is not banked Explain the need of banking of road Distinguish between centripetal and centrifugal force Explain why centrifugal force is called as pseudo force Draw neat diagram of force acting on vehicle moving along banked road What is conical pendulum? Safe Hands

Define angular velocity, angular acceleration and give their directions Define angular velocity, angular acceleration and give their SI units Define UCM and obtain relation between linear and angular velocity Explain centripetal and centrifugal force Derive an expression for centripetal acceleration Define angle of banking and obtain expression for the same. Write Newton’s equations for rotational motion. Obtain expression for time period of conical pendulum. Safe Hands

Important formulae of CM Safe Hands

Total marks 3/5 Questions may be of 1,2,3,4 marks Gravitation Total marks 3/5 Questions may be of 1,2,3,4 marks Safe Hands

Questions for 2 marks State Newton’s law of gravitation, give SI unit and dimensions of constant of gravitation Obtain relation between gravitation constant and gravitational acceleration at certain height from surface of earth Obtain relation between gravitational acceleration at certain height from surface of earth and on surface of earth Safe Hands

Explain why two stage rocket is necessary to launch a satellite State the conditions under which satellite will move in parabolic and elliptic path Derive the expression for critical velocity of a satellite. Derive an expression for period of a satellite revolving round the earth Explain communication satellite and give its two applications Safe Hands

Safe Hands Define escape velocity and binding velocity Obtain expression for binding energy of a body at height h above the surface of earth when it is at rest Obtain expression for escape velocity of the satellite on surface of earth Explain weightlessness State Kepler’s laws of motion Draw and explain the graph of ‘g’ and distance from centre of earth. Safe Hands

For 4 marks Define critical velocity and obtain expression for it and state the factors on which it depends Obtain expression for critical velocity of a satellite at height h and obtain expression for period Define binding energy and obtain expression for the same at rest on earth surface Orbiting at height h above the surface Safe Hands

Important formulae of gravitation Safe Hands

Possible questions are of 1,2,3 or 4 marks Rotational Motion Total marks 4/6 Possible questions are of 1,2,3 or 4 marks Safe Hands

2 marks Safe Hands Define Rigid body and Moment of inertia Radius of gyration and moment of inertia Explain physical significance of MI Compare MI of solid sphere and hollow sphere of same mass and of same material Show that total KE of a sphere of mass m rolling along horizontal plane with velocity v is 7mv2/10 and similar Deduce an expression of KE of rolling body Safe Hands

Prove that torque equals product of angular velocity and moment of inertia State principle of parallel axis theorem Principle of perpendicular axis theorem Show that MI of thin uniform rod about an axis passing through a point midway between center and edge, perpendicular to it is 7ML2/48 ( and similar) Using parallel axis theorem and MI of axis of length L, mass m about an axis perpendicular to rod is ML2/12 obtain MI about an axis perpendicular to rod and through edge Safe Hands

MI of solid sphere about its diameter is 2MR2/5 with usual meaning then determine MI about tangent Assuming MI of a uniform disc about an axis passing through its center and perpendicular to its plane, obtain an expression for its MI about any diameter show that MI about tangent is 5MR2/4 Show that MI about axis passing through edge and perpendicular to plane of disc is 3MR2/2 State the principle of conservation of angular momentum and explain it with suitable example State and prove law of conservation of angular momentum Safe Hands

3 marks each Define radius of gyration and give its physical significance State and prove principle of parallel axis about moment of inertia State and prove principle of perpendicular axis about moment of inertia Derive expression for MI of a rod of mass M and length L about an axis passing through its center and perpendicular to it, hence obtain MI about an axis perpendicular to it and passing through one of its edge Safe Hands

Important formulae of MI Safe Hands

Total marks 5/7 Possible questions may be of 1,2,3 or 4 marks Oscillation Total marks 5/7 Possible questions may be of 1,2,3 or 4 marks Safe Hands

Periodic motion, Linear SHM Phase of a particle performing SHM 2 marks question Define Periodic motion, Linear SHM Phase of a particle performing SHM Amplitude, Period for particle in SHM Angular SHM, force constant Phase and epoch Second’s pendulum, simple pendulum State the expression for KE and write values for KE at mean position and extreme position Safe Hands

Show that PE of a particle is directly proportional to the square of its displacement from mean position Assuming expression for KE and PE of a particle performing SHM obtain expression for TE and deduce conclusion from it. Define second’s pendulum and show that length of seconds pendulum is constant at given place Deduce an expression for period of a particle performing SHM in terms of force constant Draw diagram showing displacement and velocity against time Safe Hands

Obtain expression of velocity using differential equation of SHM Obtain expression for period of simple pendulum State differential equation for angular SHM give one example for the same. Represent KE and PE against displacement in separate graphs with proper labeling Write down at what distance from mean position the KE =PE and at what distance velocity will be half of maximum Safe Hands

3 marks question Safe Hands Show that linear SHM can be considered as the projection of UCM on any diameter Represent graphically the displacement, velocity and acceleration against time for a particle performing linear SHM when it starts from extreme position Assuming general equation of displacement in SHM obtain expression for velocity and acceleration Obtain expressions for KE,PE and hence show that TE is constant for linear SHM Discuss analytically, the composition of two SHMs of same period and parallel to each other Safe Hands

4 marks question Safe Hands State the differential equation of SHM and obtain expression for displacement, velocity and acceleration Obtain expression for period of simple pendulum, hence calculate the length of second’s pendulum Obtain expression for the period of a magnet vibrating in a uniform magnetic induction If x1 = a1sin(t+1) and x2=a2sin(t + 2) obtain an expression for resultant amplitude hence obtain resultant amplitude when phase differ by 0o and by 90o. Safe Hands

Important formulae of Oscillation Safe Hands

Important formulae of Oscillation Safe Hands

Total Marks 4/6 Possible questions are of 1,2,3 or 4 marks Elasticity Total Marks 4/6 Possible questions are of 1,2,3 or 4 marks Safe Hands

Questions of 2 marks Safe Hands What is elasticity? How can you differentiate between elastic body and plastic body? Define deforming force and perfectly elastic body Define stress and strain, write their units Define stress, strain and their dimension What is shearing stress? State its units and dimension The graph of stress against strain is as shown in adjoining figure, state what points E,Y and C represents, define any one of them Safe Hands

Safe Hands Define bulk modulus & derive expression for it. What is elastic limit? What happens beyond elastic limit? State Hooks law of elasticity and define modulus of elasticity Explain why only solids posses all the three constants of elasticity Deduce an expression of Young’s modulus of material of a long uniform wire Assuming Hook’s law show that Young’s modulus of the material of a wire is the stress required to double the length of wire Safe Hands

Safe Hands Define modulus of rigidity and derive its necessary formula Prove that deforming force is directly proportional to the change in the volume of a wire in the case of Young’s modulus Define Yield point, Breaking point Explain why two identical wires of the same material used in method for the determination of Y Safe Hands

Questions for 3 marks Safe Hands 18. Define strain and explain its different types What is Poisson’s ratio? Why it does not have any unit? Give the expression of sag of horizontal beam and explain terms used in it. How will you relate ductility and brittleness with stress strain graph. Give examples of both types. Define thermal stress and relate it with coefficient of linear expansion and Young’s modulus. Safe Hands

Questions for 4 marks Safe Hands Derive expression for work done per unit volume in stretching a wire With the graph explain behavior of a wire under increasing load Prove that strain energy per unit volume equals (stress x strain)/2 Safe Hands

Important formulae Safe Hands

Total marks 4/6 Question may be of 1,2,3 or 4 marks Surface Tension Total marks 4/6 Question may be of 1,2,3 or 4 marks Safe Hands

Questions of 2 marks Safe Hands Define Range of molecular attraction, sphere of influence Define Angle of contact, surface tension Define Cohesive force, Adhesive force Obtain dimension of surface tension and state its units State four characteristics of angle of contact Give applications of surface tension. Give applications of capillary action. State Laplace’s law of spherical membrane. Safe Hands

3 marks questions Safe Hands Explain formation of concave and convex surface on the basis of molecular theory Explain why angle of contact is acute for water – glass interface and is obtuse for mercury –glass pair Explain the term angle of contact, What is the nature of an angle of contact for a liquid which partially wets and does not wet the solid State expression for rise of liquid in capillary tube and explain the factors affecting the rise of liquid Safe Hands

4 marks questions Safe Hands Explain surface tension on the basis of molecular theory What is surface energy? Establish relation between surface tension and surface energy Using molecular theory explain why the free surface of some liquids in contact with a solid is not horizontal What is capillarity? How it is used to determine surface tension of a liquid which wets the glass. State Laplace’s law of spherical membrane and prove it. Safe Hands

Important formulae of properties of liquid Safe Hands

Total marks 3/5 Questions may be of 1,2,3 or 4 marks Wave Motion Total marks 3/5 Questions may be of 1,2,3 or 4 marks Safe Hands

Questions of 2 marks Safe Hands Wave is doubly periodic phenomenon, explain State any four characteristics of simple harmonic progressive wave Define Longitudinal, Transverse wave State any four characteristics of longitudinal wave State any four characteristics of Transverse wave Distinguish between Transverse and Longitudinal waves State and explain principle of superposition of sound waves with the help of constructive and destructive interference Safe Hands

Safe Hands What are the conditions for beat formation What are beats? State two applications of beats What is Doppler's effect? State any two applications Draw neat labeled diagram of Quincke's tube. Safe Hands

Questions for 3 marks Safe Hands Obtain equation of simple harmonic progressive wave in positive direction of X axis Explain the phenomenon of reflection of sound waves from denser medium and from rare medium Explain the phenomenon of reflection of transverse waves from denser medium and from rare medium State and explain principle of superposition of waves Explain method of determination of wavelength of sound using Quincke’s tube. Safe Hands

Questions for 4 marks Safe Hands 01. Obtain expression for progressive wave and write it in two different form 02. Using analytical treatment show that the beat frequency is equal to difference between frequencies of interfering waves. 03. Describe construction of “ Quincke’s tube” and how it works? 04. Explain Doppler's effect in sound. Give mathematical expression for frequency and its application. Safe Hands

Important formulae for wave mechanics AR Safe Hands

Total marks 5/7 Questions may be of 1,2,3 or 4 marks Stationary Waves Total marks 5/7 Questions may be of 1,2,3 or 4 marks Safe Hands

2 mark questions Safe Hands What are stationary waves and why they are called so? State any four characteristics of stationary waves What are the conditions of stationary waves? What are nodes and antinodes? State the difference between harmonics and overtone State expression for frequency of vibrating string hence show that n is inversely proportional to radius and root of density of wire Safe Hands

Safe Hands Explain resonance Explain forced and free vibrations Describe construction of Sonometer What is end correction? How to estimate end correction? State any two laws of vibrating string Draw Diagrams showing parallel and perpendicular position Draw Fundamental mode of vibrating air columns in open and close pipe Draw First and second harmonics of string Safe Hands

Safe Hands Distinguish between Harmonics and overtone Distinguish between stationary and progressive waves Distinguish between free and damped vibrations State the formula for fundamental frequency of string explain terms used State the formula for fundamental frequency of vibrating air column in open pipe and explain terms used State the formula for fundamental frequency of vibrating air column in pipe closed at one end and explain terms used Safe Hands

3 marks questions Using analytical method derive expression for resultant displacement of two progressive waves traveling in opposite directions. Why it is called as stationary wave. Explain vibration of stretched string fixed at two ends. State the formula for fundamental frequency and explain laws of vibrating string Safe Hands

Explain the working of flute. Explain working of harmonium. 3 marks questions Explain why all harmonics are present in air vibrating in a pipe open at both ends and not in pipe close at one end. Explain the terms forced vibration and Resonance and give two applications of resonance. Explain the working of flute. Explain working of harmonium. Safe Hands

Questions of 4 marks Describe Melde’s experiment to determine frequency of tuning fork in perpendicular position. Describe Melde’s experiment to determine frequency of tuning fork in parallel position. Explain how velocity of sound can be measured using resonance tube Safe Hands

Important formulae for Stationary waves

Kinetic theory of gases and Radiation Total marks 4/6 Possible questions may be of 1,2,3 or 4 marks Safe Hands

Questions for 2 marks Safe Hands Explain the terms free path, mean free path Explain cause of pressure on close container Define mean square velocity, root mean square velocity Deduce Boyle’s law on the basis of KTG Assuming the expression for pressure exerted by the gas show that kinetic energy per mole of gas is 3RT/2N Explain why gases have two specific heats Explain Cp greater than Cv Safe Hands

Questions for 2 marks Assuming the expression for pressure exerted by the gas show that P.V=2(TKE) / 3 Define ideal gas. Show that KE per unit volume of a gas is directly proportional to atmospheric pressure. Define molar specific heats of gas Define principle specific heats of gas Define internal latent heat. Safe Hands

2 mark questions Safe Hands Define coefficient of absorption and reflectance. Define coefficient of absorption and of transmission. Obtain relation between a, r and e. Define coefficient of transmission. If t = 0 then what type of body it is? give example. Explain construction and working of perfectly black body. What do you mean by black body. State the use of conical projection of an artificial black body. Define emissive power and emissivity of body. Safe Hands

2 mark questions Safe Hands Define emissive power and list the factors on which it depends. State Kirchhoff's law of radiation and Stefan’s law of radiation. State Stefan's law for radiation. Write unit of Stefan's constant. State Wien's law of radiation. Write unit of “b” State the limitations of Newton’s law of cooling. State Prevost’s theory of heat exchange. Write two observations of energy diagram of black body radiations. Safe Hands

Questions for 3 marks Safe Hands State any two assumptions of Kinetic theory of gases and show that RMS velocity is directly proportional to square root of absolute temperature. State any two assumptions of KTG and obtain Boyle’s law. Define principle specific heats and explain why cp > cv What are degree of freedom and state law of equipartition of energy. State Dalton’s law and Charle’s law Safe Hands

3 marks questions Safe Hands Define coefficient of absorption, emission and transmission and obtain relation between them. What do you mean by perfectly black body? Can it be realized in practice? How will you construct perfectly black body? Give theoretical proof of equality of emissive and absorptive power. State Stefan’s law, Newton’s law and Kirchhoff’s law. Obtain Newton’s law using Stefan’s law. Safe Hands

( Rigid) Diatomic gas is 7/5 (Non rigid) Diatomic gas is 9/7 Questions for 3 marks Using specific heat capacities show that adiabatic constant of ( any one ) monatomic gas is 5/3 ( Rigid) Diatomic gas is 7/5 (Non rigid) Diatomic gas is 9/7 Polyatomic gas (4+f)/(3+f) State zeroth, first and second law of thermodynamics. Safe Hands

Questions for 4 marks Safe Hands Write any eight assumptions of KTG. On the basis of KTG obtain expression of pressure exerted by enclosed gas. Draw and explain the curve between energy and wavelength of radiations by a black body at different temperatures. State Kirchhoff’s law and give its experimental explanation. State & explain Prevost’s theory of heat. Derive Newton’s law of cooling using Stefan’s law. Safe Hands

Expression for terms used in KTG Useful relations for problems: ( if pressure is constant) (it temperature is constant) (if gas is same) ( if gas and temperature is different ) Safe Hands

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Important formulae for Radiation a + r + t = 1 Safe Hands