CLASS: XI Subject: PHYSICS (BLUE PRINT)

Max.Marks:70

UnitNo.

Name of the UnitVSA

(1 mark)

SA-I

(2 marks)

SA-II

(3 marks)

VBQ

(4 marks)

LA

(5 marks)

Total

M (Q)

1Physical world and Measurement

3 (1) 3 (1)

2 Kinematics 2 (1) 3 (1) 5 (1) 10 (3)

3 Laws of motion 1 (1) 2 (1) 3 (1) 4(1) 10 (4)

4Work, energy and power

6 (2) 6 (2)

5Motion of system of particles and rigid body

6 (2) 6 (2)

6 Gravitation 2 (1) 3 (1) 5 (2)

7Properties of bulk matter

2(2) 3 (1) 5 (1) 10 (4)

8 Thermodynamics 2 (1) 3 (1) 5 (2)

9Behavior of perfect gas and kinetic theory of gases

2 (1) 3 (1) 5 (2)

10 Oscillations and waves 2(2) 3 (1) 5 (1) 10 (4)

Total 5⨉1=5 5⨉2=10 12⨉3=36 1⨉4=4 3⨉5=15 70 (26)

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CLASS - XI SUBJECT- PHYSICS (THEORY)Time: 3:00 Hrs. Max. Marks: 70____________________________________________________________________

General Instructions : (i) Please check that this question paper contains five printed pages(ii) All questions are compulsory.(iii) There are 26 questions in total. Questions 1 to 5 are very short answer questions and carry one mark each.(iv) Questions 6 to 10 carry two marks each, questions 11 to 22 carry three marks each, Question 23 is value-based question carry four marks and questions 24 to 26 carry Five marks each.(v) 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 .You have to attempt only one of the given choices in such questions.(vi) Use of calculators is not permitted. However, you may use log tables if necessary.(vii)You may use the following physical constants wherever necessary: c= 3 x 10 8 m/s ; G = 6.6 x 10 -11 N/m2/kg-2 : R = 8.314 mol -1K-1

me = 9.1 x 10 -31 kg ; g = 9.8 m/s2

______________________________________________________________________

Q1 A force of 49 N is just sufficient to pull a block of wood weiighing 10 kg on a rough horizontal surface. Calculate the coefficient of friction and angle of friction

1

Q2 N ame the type of flow of the fluid in fig (a) and fig (b) 1

Q3 Why is the tip of the nib of a pen split? 1

Q4 A steel wire 0.72 m long has a mass of 5.0 ×10–3 kg. If the wire is under

a tension of 60 N, what is the speed of transverse waves on the wire ?

1

Q5 Draw the displacement versus time graph for the damped harmonic oscillations. 1

Q6 A particle starts from rest and its acceleration ‘a’ is plotted against time ‘t’ as shown. Name the type of motion and also plot its velocity – time graph.

a

2

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o t

Q7 A bullet of mass 0.04 kg moving with a speed of 90 m s-1 enters a heavy wooden block and is stopped after a distance of 60 cm. What is the average resistive force exerted by the block on the bullet?

2

Q8 State and explain Kepler’s first and second law of planetary motion. 2

Q9 Give one main differences between reversible and irreversible processes along with an example for each one of them.

2

Q10 Define rms speed of a gas molecule. Write its expression interms of temperature

(OR)

What is the relation between pressure and average kinetic energy of an ideal gas ? Also Give the kinetic theory interpretation of temperature.

2

Q11 The frequency ‘f’ of vibration of a stretched string depends upon i) Its length ‘l’ ii) its mass per unit length ‘m’ and iii) the tension ‘T’ in the string.

Obtain dimensionally an expression for frequency ‘f’ of the vibrationThe value of the constant is equal to ½

3

Q12 Look at the graphs (a) to (c) carefully and state, with reason, (why or why not ) which of these cannot possibly represent one-dimensional motion of a particle. x, v and t mentioned in the graphs are position, velocity and time respectively.

3

Q13 A vehicle is taking a circular turn on a level road. With the help of a neat and labeled 3Page 3 of 9

diagram, obtain the expression for the speed limit with which it can negotiate the curved track

Q14 a) State the theorems of Moment of Inertiab)Obtain the expression for the Moment of Inertia of a uniform circular disc of radius ‘R’ and mass ‘M’ about an axis i) passing through its centre and normal to disc ii)passing through a point on its edge and normal to the disc.The moment of inertia of the disc about any of its diameter is given tobe ¼ MR2

3

Q15 a) State the law of conservation of angular momentum . b) A horizontal disc rotating about vertical axis makes 100 revolutions per minute. A small piece of wax of mass 10 g falls vertically on the disc and adheres to it at a distance of 9 cm from its axis. If the number of rotations per minute is thereby reduced to 90, calculate the moment of inertia of the dis

3

Q16 i) Give two main properties of elastic collision. ii) Obtain the expressions for the final velocities of two bodies undergoing elastic collision in one dimension .

3

Q17 a) State work – energy theorem. Give its expression. b) A water pump pumps out 2400 kg water per minute. i) If water is coming out with a velocity of 3 m/s , what is the power of the pump? ii) How much work is done if the pump runs for 10 hours?

3

Q18 Define orbital velocity of a satellite. Derive an expression for orbital velocity of the satellite interms of mass of the planet and Gravitational constant ,with a neat labeled diagram.

3

Q19 Two wires of diameter 0.25 cm, one made of steel and the other made of brass are loaded as shown in Fig. given below. The unloaded length of steel wire is 1.5 m and that of brass wire is 1.0 m. Young’s modulus of steel is 2.0 x 10 11 Pa and that of brass is 0.91 x 10 11 Pa. Compute the elongations of the steel and the brass wires.

3

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(OR)

a)Define coefficient of linear expansion of a solidb)A brass rod of length 40 cm is joined to a copper rod oflength 50 cm.The two rods are of the same thickness and at initial temperature of 40 ° C. What is the change in length of the combined rod , when the same is heated to 280°C? . Coefficient of linear expansion of brass and copper are 1.9 x 10 -5 ° C-1 and 1.7 x 10 -5 ° C-1 respectively.

Q20 What is meant by degrees of freedom? Write its expression. Using it obtain the value of the degrees of freedom for i) a diatomic gas ii) triatomic gas at ordinary temperature.

3

Q21 Show that for small oscillations , the motion of a simple pendulum is simple harmonic. Drive an expression for its time period using necessary diagram.

3

Q22 With the necessary block diagram explain the working principle of a heat engine and obtain the expression for its efficiency.

3

Q23 A monkey is sitting on a tree. Rahim , seeing the Monkey brought some fruits and gave them to the Monkey, and ran into his house immediately. On hearing the sound produced when Rahim was running ,the monkey was scared and climbed the nearby tree. (a) What values of Rahim inspired you? (b) A monkey of mass 40 kg climbs on a rope which can stand a maximum tension of 600 N . In which of the following cases will the rope will break.; the monkey (i) Climbs up with an acceleration of 6 m/s2 (ii) Climbs down with an acceleration of 4 m/s2

(Take g= 10 m/s2) (Ignore the mass of the rope)

4

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Q24 i) A projectile is fired with a certain velocity ‘u’ , making an angle ‘Θ’ with the horizontal. With necessary diagram ,prove that the trajectory of the projectile is a parabola and obtain the expression for it’s a) Time of flight b) maximum height reached and c) horizontal range of the projectile

(OR)i) From the velocity –time graph of a uniformly accelerated motion of a body deduce it’s position – time relation. ii) The displacement ‘x’ of a particle varies with time ‘t’ as x= 4t2 – 15 t + 25 where x is in ‘m’, and time in sec. Find the position , velocity and acceleration of the particle at t = 0 s.

5

Q25 i)State Pascal’s law and give a brief experimental verification of Pascal’s lawii)With the help of a labeled, diagram , explain the working of hydraulic brake

(OR)i)Define surface tension and surface energy of a liquid ii) With necessary diagram, prove that the surface tension of a liquid is numerically equal to its surface energy

5

Q26 i) Name the principle involved in the formation of beats.ii) With necessary diagrams , explain the formation of beats analytically and

obtain the expression for beats frequency.

(OR)

i) What are standing waves?ii) With necessary diagrams , explain the formation of standing waves in a stretched string, fixed at both the ends and also obtain the expression for the frequency of its first three modes of vibration.

5

Q.No Value points Marks1 µ = f/R = 0.5

tan ϴ = 0.5 , ϴ = 26 ̊ 34’ ½½

2 a) Streamline flow b) turbulent flow ½ +½3 It acts as a capillary tube that allows ink to rise up due to capillary action so that we are

able to write with the pen1

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4

½

½

5 Correct graph 16 i) Uniformly accelerated motion

ii) Correct v-t graph11

7 The retardation ‘a’ of the bullet

The retarding force, by the Second Law ofmotion, is F = ma= 0.04 kg x 6750 m s-2 = 270 N

½½

½½

8 Statementsexplanation

½ +½½ +½

9 Any one correct point of difference One correct example for each

11

10 DefinitionCorrect expression v rms = square root of 3kT/m (OR)

The pressure of an ideal gas is two third of its average kinetic energy per unit volume of the gas molecules. The average kinetic energy of a gas molecule = 3kT/2 It is proportional to the absolute temperature T of the gas

11

1

½½

11 Writing the correct dimensions of the given physical quantitiesDerivation of the expression f = 1/2l x square root of T/m

12

12 a) No, because two different positions at same time is not possibleb) No, because two different velocities at same time is not possiblec) No, because speed cannot be negative

½ +½½ +½½ +½

13 Correct diagram

Derivation of the expression v =

12

14 a) Statements of parallel and perpendicular axes theoremsb) i) I = Ix

+ Iy

½+½½

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= ½ MR2

ii)I = I c + M h 2

= 3/2 of MR2

½½½

15 a) Correct Statementb) L = I1 ω1 = I2ω2

MI of the disc and wax, I2 = I1 + mr2

I 1 = 7290 g cm2

1½½1

16 i) Two correct propertiesii) Expressions of momentum conservation and kinetic energy conservation

Final and correct expressions of v 1 and v2

½+½½ +½

½ +½17 a) Work – energy theorem statement with expression

b) i) W = change in KE = ½ mv2 - ½ mu2 = 10800 J P = W / t = 10800 / 60 = 180 W ii)W = P x t = 180 x 10 x 60 x 60 = 6.48 x 106 J

½ +½½½1

18 Correct definitionCorrect diagramDerivation

½½2

19 Y = Fl /AΔlΔl for steel = 1.5 x 10 -4 m Δl for blass = 1.3 x 10 -4 m (OR)For Brass rod l’ = l ( 1 + α ΔT) = 40.18 cmFor copper rod l’ = l ( 1 + α ΔT) = 50.2 cmAt 40 °C combined rod length = 90 cmAt 280 °C combined rod length = 90.39 cm.Change in length = 0.39 cm

111

½+½½+½

½½

20 Definition and expression f = 3 N - kValue for diatomic gas = 5Value for triatomic gas = 6

½+½11

21 DiagramTo prove that acceleration is proportional to negative displacement Derivation of time period

11 1

22 Block diagram Working principle ExplanationExpression for its efficiency

111

23 Ans: (a) Any 2 correct values like Rahim loves animals and feeds them, taking care of animals doesn’t frighten animals (b) (i)The tension developed in the string when the monkey climbs up with an acceleration of 6 m/s2 is given by T = m(g + a) = 40 (10 + 6) =640 N (ii ) The tension developed when the monkey climbs down with an acceleration of 4m/s2 is given byT = m(g-a) = 40(10-4) = 40 x 6 = 240 N Since the string can withstand a maximum tension of 600 N,

2

½

½

1

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hence the rope will break only in the first case (i)24 i)Diagram and derivation of the equation of the trajectory

a)Derivation of Time period b)Derivation of maximum height c) Derivation of Range

(OR)i) Graph Derivation from the graph S = ut + ½ at2

ii) x =4t2 – 15 t + 25 = 25 m v= dx/dt = 8t – 15 = 15 m/s a = dv/dt = 8 m/s 2

½+1½ 1

11

11111

25 i)Statement experimental verificationii)correct diagram working explanation

(OR)i)Definition of surface tension and surface energyii)Diagram Proof

1 1

1 2

1+1 12

26 i) Superposition principleii) Diagrams

Derivation of beats frequency (OR)

i) definition of standing waves ii) diagrams of 3 modes of vibrations iii) expressions for frequencies of first 3 modes of vibrations

113

11

1+1+1

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