SESSION ENDING EXAM
BLUE PRINT
UNITS / 1 MARK / 2 MARK / 3 MARK / 4 MARK / 5 MARK / TOTAL- MEASUREMENTS
- KINEMATICS
- LAWS OF MOTION
- WORK, ENERGY AND POWER
- MOTION OF SYSTEM OF PARTICLES AND RIGID BODY
- GRAVITATION
- PROPERTIES OF BULK MATTER
- THERMODYNAMICS
- BEHAVIOUR OF PERFECT GAS & KINEMATIC THEORY OF GASES
- OSCILLATIONS & WAVES
TOTAL / 5 / 5 / 12 / 1 / 3 / 70 (26)
SESSION ENDING EXAMINATION
SUB: PHYSICS
CLASS - XI
TIME: 3 HOURSM.M: 70
Please check that this question paper contains 26 questions.
Please write down the serial number of the question before attempting it.
15 minutes time has been allotted to read this question paper. The students will read the question paper only and will not write any answer on the answer-book during this period.
General Instructions:
(i)All questions are compulsory.
(ii)There are 26 questions in total. Questions 1 to 5 are very short answer type questions and carry one mark each.
(iii)Questions 6 to 10 carry two marks each, questions 11 to 22 carry three marks each and questions 24 to 26 carry five marks each.
(iv)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 choices in such questions.
(v)Question 23 is a value based question carrying four marks.
(vi)Use of calculator is not permitted. However, you may use log tables if necessary.
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1 A ball is thrown vertically upwards. Draw its velocity –time curve. / 12State if the following statement is true or false. Give reasons for your answer. 1 “Work done in the motion of a body over a closed loop is zero for every force in nature “.
3Define modulus of rigidity of a material. Give its S.I unit.1
4The ratio of vapour densities of two gases at the same temperature is 16:9. 1 Compare the r.m.s velocities of their molecules.
5 / State the law of equipartition of energy. / 16 / A bullet of mass 60 g, moving with a velocity of 500 m/s, is brought to rest in / 2
0.01 s. Find the impulse and the average force of blow.
7 / Show that instantaneous power of an agent is equal to the dot product of its / 2
force and velocity vector at that instant.
8 / Define radius of gyration of a cylindrical rod of mass m and length L about an / 2
axis of rotation perpendicular to its length and passing through its centre.Giveits S.I. unit.
OR
A particle performs uniform circular motion with an angular momentum L. If the
frequency of particle’s motion is doubled and its K.E is halved, what happens to
the angular momentum?
9 / What was wrong in the assumption made by Newton to obtain the speed of / 2
sound in air. How did Laplace correct it? Write Newton’s & Laplace’s formula for
speed of sound in air.
10 / A horizontal force / of 20 N is necessary to just hold a block against a wall, / 2
find the weight of / the block, if the coefficient of friction between the block
and the wall is 0. 2.
11 / What is meant by parallax? How can you find the distance of / a star or a / 3
distance planet from the earth by parallax method?
12 / Gases have two specific heats, but the solids and liquids possess only one / 3
specific heat. Why? Using first law of thermodynamics, obtain / the relation
between the two specific heats of a gas.
13 / A rocket is fired from the earth towards the sun. At what distance from the / 3
earth’scentre is the gravitational force on the rocket zero? Mass of the sun = 2
x 1030 kg, mass of the earth = 6 x 1024 kg, orbital radius of the earth = 1.5 x 1011
m. (Neglect the effect of other planets etc.)
14 / Name the physical quantity which is the rotational analogue of force and give its / 3
S.I unit. Obtain a relation of this quantity with the angular momentum.
15Two masses M and m are connected at the two ends of a inextensible string. The string passes over a smooth frictionless pulley. Calculate the acceleration
of the masses and the tension in the string. (M>m).3
16Give the magnitude and direction of the net force acting on a stone of mass 0.2 kg just after it is dropped from the window of a.(Neglect air resistance throughout) , g=10 m/s2 3
(a)stationary train.
(b)train running at a constant velocity of 36 km/h.
(c)train accelerating with an acceleration of 1m/s2 .
17 / Obtain an expression for the acceleration due to gravity at a depth ‘d ’ from the / 3surface of the earth of mass ‘ M ‘ and radius ‘R’ . Using the expression find the
weight of a body of mass ‘m ‘ at the centre of the earth ?
18 / Define Latent heat of fusion. When 0.15 kg of ice of 0 0C is mixed with 0.30 kg / 3
of water at 50 0C in a container, the resulting temperature is 10 0C. Calculate
the latent heat of fusion of ice. (Specific heat capacity of water = 4200 J/Kg/K)
OR
What is meant by coefficients of linear expansion, superficial expansion and cubical expansion? Derive expansion and cubical expansion? Derive the relationship between them
19 / State Kelvin’s statement of second law of thermodynamics. Draw the Carnot / 3cycle for a heat engine with an ideal gas as the working substance. Write the
expression for the efficiency of the Carnot’s heat engine. Explain why the
efficiency of a heat engine cannot be 100 %.
20 / A spring having with a spring constant 1200 N/m is mounted on a smooth / 3
horizontal table as shown in fig. A body of mass 3 kg is attached to the free end
of the spring. The body is then pulled sideways to a distance of 2.0 cm and is
released.
Determine (i) the frequency of oscillations. (ii) Maximum acceleration of the mass, and (iii) the maximum speed of the mass.
21 / State work energy theorem. Derive the work-energy theorem for a variable / 3force.
22 / Write the expression of the pressure exerted by a gas in terms of density and / 3
r.m.s velocity. Show that the pressure exerted by a gas is 2/3rd of the average
Kinetic energy per unit volume of the gas molecules.
23 / Sumit was very interested in Javelin throw. He wanted to participate in the / 4
National and International level events. But he was very frustrated and wanted to quit the same as the range of the throw was not satisfactory to take part in the National level and International level events. His friend Sunil encouraged him to do practice more and advised him consult with the PET in the school. His teacher listened to his problem and advised him that he should throw the Javlin at an angle of 450 for maximum horizontal range. He did the same and his throw improved day by day and he started participating in competition.
(i)What moral value did you get from the above example?
(ii)Write the expression for the horizontal range of an oblique projectile and hence expression for the maximum horizontal range.
(iii)A body is projected with speed u at an angle to the horizontal to have maximum range. What is its velocity at the highest point?
24State Bernoulli’s Principle. Name a device based on this principle used to measure the flow of incompressible fluid. Derive an expression for the speed of incompressible fluid flowing through a cylindrical pipe. 5
OR
Define surface tension and surface energy. Find a relation between the two? A liquid drop of radius 1 cm is spread into 106 droplets of equal size. Calculate the energy expended? Surface tension of the liquid 32 x 10-2 N/m.
25What is Doppler Effect in sound? Obtain an expression for the observed frequency of sound produced by a source when the observer is moving towards
the stationary source and the medium is at rest.
What is the frequency of the whistle heard by a man running
- Towards the engine with a speed of 10 m/s
- Away from the engine with a speed of 20 m/s.
The true frequency of the whistle is 400 Hz; Speed of sound is 340 m/s.5
OR
Find the expression of the time period T of the of a pendulum for small amplitude of effective length ‘l’ and mass of the bob ‘m’ ,acceleration due to gravity ‘g’ .
How the time period will change if
- Length of the pendulum is increased to 4 times
- Mass of the bob is decreased to 1/3 times
- The pendulum is in a constant accelerated ascending lift?
26State parallelogram law of vector addition .Two vectors A and B are inclined at an angle θ. Find the expression for their resultant and direction from the law of parallelogram.
Two vectors A and B are such that |A+B| = |A-B|, find the angle between A and B.
OR
Draw velocity – time graph for uniformly accelerated motion. Obtain position time relation from the graph.
A ball is thrown vertically upwards with a velocity of 20 m/s from the top of a building. The height of the point form where the ball is thrown is 25 m from the ground. (a) How high will the ball rise? and (b) how long will it be before the ball hits the ground ? (g= 10 m/s2)
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Marking Scheme
Q No. / Answers / Marks1 / For graph / 1
2 / False, for non conservative force it is not zero like friction / ½+ ½
3 / Definition , Unit / ½ + ½
4 / Formula , calculation and result / ½ + ½
5 / Statement / 1
6 / Calculation of impulse
Calculation of force / 1
1
7 / For derivation give full marks / 2
8 / Definition, formula, unit
Or
L= Iω, calculation and answer / 1+½ + ½
½+1+ ½
9 / Correct assumption, formulae / ½+ ½ + ½ + ½
10 / Formula, calculation and answer / ½ + 1+ ½
11 / Explanation, diagram and method / 1+ 1 +1
12 / Explanation and derivation of relation( Mayer’s formula) / 1+2
13 / Formula, calculation and answer / ½ +2 + ½
14 / Torque, unit and derivation of relation / ½ + ½ +2
15 / Derivation of acceleration and tension / 1 ½ + 1 ½
16 / Calculation of net force (a+b+c) / 1+1+1
17 / Derivation, Mass of body at the centre of earth / 2+1
18 / Definition, formulae, calculation and result
Or
Definitions, relations / 1+1+1
½ + ½ + ½ +1 ½
19 / Statement, Diagram Expressions and Explanation / 1+1+1
20 / Formula, calculation and answer / ½ +2 + ½
21 / Statement and Derivation / 1+2
22 / Derivation / 3
23 / Values, Expression and velocity / 2+1+1
24 / Statement, Device, Derivation
Or
Definition, Relation and Calculation / 1+ ½ + 3 ½
Or
1+1+1+2
25 / Definition, Expression and Calculation
Or
Definition, Expression and Calculation / 1+2+2
Or
1+2+2
26 / Definition, Expression and Calculation
Or
Graph, Derivation and Calculation / 1+2+2
Or
1+2+2