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1 Downloaded from BLUE PRINT XI PHYSICS osbincbse.com Sr. no Name of chapters VSAQ () Physicsl world and measurement Kinematics Laws of motion Work Energy and Power System of particle and Rotational motion Gravitation Properties of bulk Thermodynamics Behavior of perfect gasses and kinetic theory of gasses Oscillations and waves SA-I () SA-II () Value based (4) LA(5),, QUESTION PAPER XI PHYSICS Time: Three Hours Maximum Marks: 70 General Instructions (a) All questions are compulsory. E. C OM (b)there are 6 questions in total. Questions in section A carry one mark each, questions in section B carry two marks each, questions in section C carry three marks each, questions in section D carry 4 marks and questions in section E carry five marks each. IN C (d)use of calculator is not permitted. BS (c) There is no overall choice. However, an internal choice has been provided in one question of two marks, one question of three marks and all three questions of five marks each. You have to attempt only one of the given choices in such questions. OS B SECTION A. If g is the acceleration due to gravity and is wave length then which physical quantity does ( g) represent?. What is the angle of friction between two surfaces in contact, if coefficient of friction is?. Define the term radius of gyration. 4. State the Kelvin-Planck statement of the second law of thermodynamics. Downloaded from

2 5. Write degrees of freedom of a triatomic linear molecule. osbincbse.com SECTION B A nucleus is at rest. All of a sudden it splits into two small nuclei.what is the angle at which these two nuclei fly apart? 8. Name the satellites which have Sun synchronous orbit. How is their orbit different from that of the satellites used for communication purpose? What is the significance of negative total energy of a satellite? 9. What is an indicator diagram? What does the area between P-V curve and volumeaxis signify? 0. Mention two advantages of I shape of iron beams used in building construction. 7. OR What is modulus of elasticity? Give its SI unit and dimension. SECTION C A physical quantity X is given by X = A B /C D, If the percentage errors of measurement in A,B,C and D are 4%,%,% and % respectively, then calculate the % error in X. 6.. Define relative velocity and derive expression for it. The motion of a car along y-axis is given by v(t)= -t + where velocity v is in m/s and time t in seconds. Find the instantaneous position of the car as a function of time if at t = 0 it was at 5 m. Also find its acceleration at t = second. 4. Prove that nd law of motion is real law of motion. 5 Derive relation between angular momentum and linear momentum.how do we find direction of angular momentum? 6. Derive an expression for escape velocity of a satellite. OR Water is flowing with a speed of m/s in a horizontal pipe with cross sectional area 0 - m at pressure Pa. What will be the pressure at a smaller cross section where the area decreases to 0.0 m? 8. State and explain first law of thermodynamics. Discuss its use in isothermal and adiabatic processes

3 9.State the main features of kinetic theory of an ideal gas. osbincbse.com 0.What is Doppler effect? A whistle is being rotated in a horizontal circle. What will be the effect on the sound frequency for a listener standing (i) outside the circle (ii) at the centre of the circle.. Show that simple pendulum execute simple harmonic motion.. Show that energy of freely falling body remains conserved. SECTION D. Adarsh a student of class XI has found the factors on which the time period of oscillation of a pendulum depends and arrived at the expression T = ( constant ) X (l/g) /. He wants to know how the length of the pendulum gets affected on the surface of the moon for the same pendulum and arrived at the conclusion that it is l/6. (a) What values does Adarsh possesses?. (b)the length of a seconds pendulum on the surface of the earth is m What will be the length on the surface of the moon SECTION E 4.What is a projectile?derive an expression for i) maximum height ii) time of flight iii) horizontal range of projectile. Or What do you mean by banking of road? Derive an expression for maximum velocity of a car for the safe turn. 5.Explain the Magnus effect with respect to the motion of a moving ball. What do you understand by viscosity? Give its dimensions and SI unit. On what factors does the coefficient of viscosity of a liquid depend? Or State Stoke s law for the viscous drag experienced by the spherical body falling through a viscous liquid. Why does a spherical body achieve terminal speed? On what factors does the terminal speed depend? Give one example each of motion around us with (i)positive (ii) Negative terminal velocity.

4 6 osbincbse.com Or State and Kepler s laws of planetary motion. 6 ANSWER KEY speed /velocity. (Θ=60 0 ). Correct definition 4. No process is possible whose sole result is the absorption of heat from a reservoir and the conversion of all of this heat into work. 5. Seven

5 osbincbse.com Polar satellites - Their orbit is perpendicular to the orbit of geostationary satellites. These are used for communication purpose. Also, the height above the Earth s surface is lower. Negative sign of total energy indicates attractive nature of force between the satellite and the Earth Statement Graph 0.. Two advantages of I shape of iron beams are + (i) minimizes sagging (ii) minimizes buckling.correct error 7.5%. Definition Expression.x(t) = dt ( t )dt/ =-t /+ t+ c = -6t + t + c ½ Since, at t = 0, x(0) = 5, therefore, c = 5/ Therefore, x(t) = -6t + t + 5 m

6 / osbincbse.com Also, a dv/dt/ m/ s 4. st law from nd law rd law from nd law 5. Relation Direction 6. Expression 7 Or P +/( )[-(a / a ) ] /(0) +4[ /0-4 ] /.4 x 0 4 Pa / 8 Statement Explanation,uses Postulates of kinetic theory

7 0. Definition: The Doppler Effect is the change in frequency and osbincbse.com Wavelength of a wave for an observer moving relative to the source of the waves. (i) For the listener standing outside the circle, the whistle moves towards him as well as away from him. Therefore, the frequency will appear to increase as well as decrease. (ii) For the listener at the centre, the distance between him and the whistle remains constant. So, there will be no change in frequency.

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10 osbincbse.com. The total mechanical energy of a system is conserved if the forces, doing work on it, are conservative. a ball of mass m being dropped from a cliff of height H. Fig. The total mechanical energies E0, Eh, and EH of the ball at the indicated heights zero (ground level), h and H, are EH = mgh E mgh mv h E0 = (/) mv The constant force is a special case of a spatially dependent force F(x). Hence, the mechanical energy is conserved. Thus EH = E0 or, mgh mv h v f gh) / a result that was obtained for afreely falling body. Further, EH = Eh which implies, vh =g(h-h) and is a familiar result from kinematics.at the height H, the energy is purely potential.it is partially converted to kinetic at height h andis fully kinetic at ground level. This illustratesthe conservation of mechanical energy. (a) Adarsh is hardworking, thinks logically,having scientific temper, able to find solutions with patience. (b) Since l is proportional to g the length of the pendulum on the surface of the moon will be /6m + 4.Def. ½ i) max height.5 ii) time period.5

11 iii) horizontal range.5 osbincbse.com or definition diagram expression 5. Def. Graph and explanation 4

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13 osbincbse.com + OR Three laws (each marks)

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