Roll No.

Time : 3 Hours

Session : 2010-11

Total No. of Pages : 3

Max. Marks : 70

Ending ExaminationSubject: Physics

Class: XI

Generallnstructions: I1. Allquestions are computsory.

2. There are 30 questions in total. Question 1 to 8 carry 1 mark each. Question g to 1 8 carry Zmarks each. Question 19 to 27 carry 3 marks each and Question 28 to 30 carry 5 markseach.

3. There is no overall choice. However an internal choice have been provided in one questionof 2 marks, 1 question in 3 marks and alt the 3 question in S marks.'yo; ;;; i"-rtt#pion"only, one of the given choice in such questions.

4. Use of calcutators is not permitted.5. Youhavetousefolioyvingconstantswherevernecessary

c=3x108'm/sh = 6.67x 10-sJS

man of nutron mn = 1.G75x 10-27 pgBaltz man's constant K = 1 .38 x 10-23 JK-1Arogadro Number NA= 6.022 x 1023 J/mole.

..7.

T.

\\ 3r--' In which motion linear momentum changes but K.E. does not?-y' {r

4. " what is the time period of simple pendulum atthe centre of earth.

:;!, Write the S.l. Unit and dimensionalformuta for Gravitational constant. tl,fllf &3*

Af/ \Nhy is difficult to stop bleeding from cut in human body at high attitudes?

Wren air is blown between two balls suspended close to each other. They are attractedtowards each other, Why?

lf presiure of a gas at constant temperature is increased four times, how the velocity ofI sound in the gas will be affected?

Atrain moves a stationary observerwith speed 34ms-1. The train sounds a whisfle and iEfrequency registered by observer is f1. lf train speed is reduced to'17 m/s, the ftequencyregistered is tl. tf the speed of sound is 340 m/s, then find Ir

l2

Showthatimpuse of a force is equalto change in linearmomentum produced bytheforce.(D

Writethe ratio ofAU andA"

Atruck and Car moving with same K.E. are st-gpped by applying same retarding force bymeans of breakes which will stop at a small dis{ance?

v

39.

10.

Class: )il

State Newton,s secondacceleration.

ORSubject Physics

law of motion; on its basis derive the retation between force and

;ffififl:;tf;:13j1'#:masses 5 ks' and 6 kg. respectiverv have equarmomenta. Find,/atlOOf theif KinetiCenefgieS. s- '--rvv'r'vu rrcrvsvqual rnOmenta. Find

\Jil Find the moment of intertia of a sphere about a tangent to the sphere, given moment of

f,#ff ,#[: i!H?::t a ny of its d ia meters to;; iii i;:;]il M is mass of the sp here,,/cU9/ Define Cp and Cv. Write the relation between them.

d ^

Derive expression for particre verocity during simpre harmonic motion.g Writethedimensionofaxbintherelation.

r-'-'r-r'r'v'rrvr'^/!rv'"

) F=a{x+bt2,whereFisforce,xisdistanceandtistime.

\a/ fl::n't'"

is projected with vetocity u making angte 0 with the verticat direction. write formuta

9) Timeof Fteight(h) Horizontalrange

Find the degrees of freedom for:(a) Diatomicgas(b) Lineartriatomicmolecule.

An incident wave is represented by Y = 2osin (2x - 4t).write the expression for reflectedql from a rigid boundary(ii) from an open boundary.

Derive the equation

17.

19.

21.

s=ut+ 1 sp,tt 2

/ wheresymbolhastheirusuatmeanings.//

W/

Three identical blocks of massgs m = 2 kg. are drawn by a force 10.2N on a frictioirlesssurface. Find the tension (in N) in tre string betwee; in" on.r, B and c.Define elastic collision' Prove that bodies of identical masses exchange theirvetocities afterhead - on elastic collision. "'vqt I I rcrDDt'u excnange tn€

ORState and prove work energy theorem

Define centre "rrXr,r:*:,::::f:.r:y:"ll!"centres of carbon and oxysen atoms in the

:ffi:,T,"#J:ffflTmolecule is t ' t 3R". t-ocate t-e centre of mass or irre sas morecure

22.

lD

Class: E/>

2€l/, Define escape velocity, obtain'")*" .u*r."of earth.

Subject: Physics

an expression for escape velocity of the body from the

24.

25\

26.

Eight rain drops of radius 1 mm. each falling down with the terminal velocity of 5 cms-1combine to form a bigger drop. Find the terminal velocity of the bigger drop.

Define lsothermal Process. Derive an expression forwork done in isothermal Process.

Derive the expression for Pressure exerted by an ideal gas, using assumptions of kinetictheoryof gases.

27.. Write the formula for Kinetic energy, Potential energy and total energy of a body executing.V SHM. Provethattotalenergyisdirectlyproportionaltosquareof amplitudeandfrequency

28. (i) Define centripetalacceteration. Derive an expression forthe centripetalaccelerationof a body moving with uniform speed valong a circularpath of radius r.

(ii) ln projectile, a particle is projected such that magnitude of velocity at the topmostpointishalf ofthemagnitudeof initialvelocity. Findtheangleof projectile.

(i) State and Prove law of parlt"fogr#(ii) A projective can have the same Range R for two angtes of projection. lf t1 and t2 be

the time of fleight in the two cases then prove that :

t1t, = 2Rg

State and prove law of conservation of linear momentum.A machine gun has a mass 20 kg. !t fires 359. bullets at the rate of 4 builets persecond, with the speed of 400 ms-1. Whatfqce must be applied to the gun to keep itin Position?

ORWrite the laws of limiting friction. Show that angle of friction is numerically equaltoangle of repose.A bus moving with a speed of 36 km h-1 negotiates a level circutar road of radius 10metres. \A/hat should be the cofficient of friction so that the bus may not skid off theroad?

State and Prove Bernaulli's theorem.A watel pipe entering a hose has a diameter of 2 cm and the speed of water is 0.1ms-1. Eventually, the pipe tapers the diameter of 1 cm. Calculate the speed of waterinthetrapped portion.

ORDerive an ascent formula for the rise of liquid in a cappilary tube.Draw stress strain curve for a metallic wire, when streched upto the breaking point.Also leveleach point in the graph.

2e. (i)(ii)

(i)

(i i)

et3b/ fi)

(ii)c)

(i)(ii)

+++(o