No.

of pages - 16
COMMON COMPARTMENT EXAMINATION-2023
CLASS:XI
SUBJECT: PHYSICS (042)
Time Allowed :3 hours Maximum Marks : 70
4T: 3 T rferhaH 3ch - 70

GENERAL INSTRUCTIONS:
(1) All questions are compulsory.There are 35 questions in all.
(2) The question paper has sections: Section A, Section B, Section C, Section D and Section
E.

(3) Section Acontains 15 MCQ and 3 assertion-reasoning MCQs of 1mark each. Section B
contains 7 short answer questions of 2 marks each. Section C contains 5 short answer
questions of 3 marks each. Section Dcontains 3 long answer questions of 5 marks each
and Section E has 2 case based questions of 4 marks each.
(4) There is no overall choice, however, internal choice is provided. You have to attempt
onlyone of thechoices in such questions
**********

G-(Section-A)

(a 68.971442 m' (b) 68.9714 m'

(C) 68.971 m (dY 68.97 m'

XI-PHYSICS
 the
What is.the volume of cub
4.101 m.
Each side of a cube is measured to be
appropriate significant figures?
68.9714 m
(a) 68.971442 m' (b)
68.971 m (d) 68.97 m
(c)
9.2

(a) 4J (b) 8J

(c) 12 J (d) 16J

A constant force F=(-i+2j+ 3k)N is acting on as object. Work done by the force
the object in 4 m displacement along z-axis is :
(a) 4J (b) 8J

(C 12J (d) 16 J

9.3

(a) dyne cm (b) kPa

(c) Jm ,(d) Nm?
Which one of the following is not a unit of Young's modulus?
(a) dyne cm-2 (b) kPa

(c) Jm3 (d) Nm?

9.4

(a)

(b)

(c)

XI-PHYSI
 Which of the following examples does not represent periodic motion?
Aswimmer completing one (return) trip from one bank of a river to the other and
back.

(b) A freely suspended bar magnet displaced from its N-S direction and released.
(c) Ahydrogen molecule rotating about its centre of mass.
(d) The rotation of the carth about its axis.

(a) S0 km/h (b) 48 km/h

(c) 4S km/h (d) 42 km/h

A
car travels first half of the distance between two places with a speed of 30 km/h and
remaining half with a speed of 70 km/h. The average speed of the car for the whole
journey is:
50km/h (b) 48 km/h
(a)
(c) 45 km/h -(d 42 km/h

S.6

(a) Å× B= AB sin 9 (b) AxB= BxÃ

(c) ¢XB=AB cos

For vectors and Bmaking angle , which one of the following relations is correct?
A×B= AB sin (tÄxB-BxÃ
AxB= AB cos0 ÄxB=-BxÅ

(a) (b) IN, 3aÍrI: àt 3

(c) 0.9 N, 3atad: àil i (d) 10 N, 3iaa: à 3t

XI-PHYSICS
 aft
magnitude and direction of the net force acting on a stone of 0.1 Kg, Just
ve ne 10 m/s)
is dropped from the window of atrain accelerating with l m/s (g=
(a) 1.1N, vertically down (b IN, vertically down
(c) 0.9N, vertically down (d) 10N, vertically down
9.8

(a) qu fa (b)
(c) (a) a(b) (d) 7 (a) r T (b)
A couple is acting on a two particle system. The resultant motion willbe:
Purely rotational motion (b) Purely translational motion 9.

(c) Both (a) and (b) (d) Neither (a) nor (b)
9.9

(d)
Two systems in thermal equilibrium with a third system separately are in therm.
equilibrium with each other as well. This law is :
(a Zeroth law of thermodynamics (b). First of the
thermodynamics
(c) Second law of thermodynamics (d) Newton'slaw of cooking
9.

(ay 25J (b) 175 J

(c) -25 J (a) -175 J

An electric heater supplies 100 J to a system. lf
system performs work of 75 I. then t
incrçase in internal energy of the systenm is :
25 J (b) 175 J
(c) -25 J (d) -175 J
4
XIPHYSI
(a) 300 N 150N

(c) 75 N (d)
Assuming the earth to be a sphere of uniform mass density, by how much would a body
weigh half way down to the centre of earth if if weighed 300 N on the surface?
(a) 300 N b 150N

(c) 75N (d) Zero

faI4 -

10m, tan 10m, tanEy 3R À 37

(a)
3
10m, tan- 3dR yd (d) 10V2m, tan|
(c) 4

displacement from its initial position:

A body moves 6m north then 8 m east, the
10m, tan north of east
10m, tan east of north (b)

1Om. tan east of north (d) 1042m, tan 4

north of east
(c)

(b) 2N

(d) 10 N
(c) 5N
within 5 cm. The average
ball of mass 25 g, moving with a speed of2 m/s is stopped
A
is :
resistance offered to the ball
(b) 2 N

(d) 10 N
(c) 5N
XI-PHYSICS
(a) (b)

(c) (d)
Amountof heat required to raise the temperature of a body through IK is called it.
(a) Specific heat capacity by Heat capacity T.16

(c) Water equivalent (d) Latent heat

ms)

(a) (b) fgA TUTgÍT

Apipe 30 cm long, is open at both ends. Which

harmonic mode of the pipe resona
1.1Khz source? (Speed of sound is air =330 m/s).
(a) First harmonic (by Second harmonic
(c) Third harmonic (d) No harmonic

y9 HT 16 & 18 3TchT (A) 3r HIUI (R) YGaTT HyI t-at

(b) (A) AR (R) <I HA 3ATR (R), (A) Ì HI I

(c) (A) 4r4 (R) 344 aI

(d) (A) 344 }31 (R) T344

For question nunber 16, 17 and 18, two
statements are
Assertion (A) and the other labelled Reason(R). Select the given one labe
-
questions from the codes (a),(b), (e) and (d) asgiven below: correct answer to th

X-PHYS
 (a) Both (A) and (R)are true and (R) is the correct xplanation of (A).
(b) Both (A) and (R)are true and R) is the not correCt explanation of (A).
(c) (A) is true but (R) is false.
(d) (A) is false but (R) is true.

Assertion (A): Displacement of abody may be zero when distance travelled by it is not
zero.

Reason (R): The displacement is longer distance between initial and final positions.

Assertion (A): The earth is slowing down and as aresult the moon is coming nearer to it.
Reason (R): The angular momentum of the earth-moon system is not conserved.

Assertion (A): The machine parts are jammed in winter.

Reason (R) : The viscosity- of lubricants used in the machine increases at low
lemperature.

G-a(Section-B)

Tr G }I (cos 22.5° = 0.924)

Abatsman deflects a ball of mass 0.15 kg by an angle of 45° without changing its
ball?
initial speed which is cqual to 54 km/h. What is the impulse imparted to the
(cos 22.5924)
7 X-PHYSICS
 4.20 TÍSs, f 34R
myxd
particle
Show that the angular momentum
about any point of a single moving wi
throughoutthe motion.
constant velocity remains Constant P=m
P L=YXp 372/ OR

engine and the automobile engi

Define radius of gyration. A machine, such as steam
with a large moment of inertia, calle
etc. that produce rotational motion have a disc
flywheel. Write the use of this flywheel.

anomalous behaviour of water.

Write the practical importance on aquatic life of

Derive position-time relation from v-t graph for a uniformly accelerated motion of
object.

t=2m
27

na ballistics demonstration a police officer Ires a bullet of mass 50 g wih speed :

ms m/s on soft plywood of thickness 2 cm. The bullet emerges with ontly 4% of its ini
Vyo ms kinetic energy. What is the emergent speed of bullet?

G-GMem
catlt(R =6.4 10° m, g =10 m/s') +
gRe
W= ChaA400,ke satellite is in a circular orbit of radius 2R about the carth. How much energ
h qavI eqyirecd to transfer itto a circutar orbit of radiys 4R? (R -640" m. g i0 ms)
w=-GMim -GM
2p
Gnm
614xlo
R
1 kttPE -GWw
2 27 24) 2(2p)
 34/ OR

(i)

The angular speed of a motor wheel is

seconds.
increased from 1200 rpm to 3120 rpm in T6

(i) What is its angular acceleration, assuming the

acceleration to be uniform?
(ii) How many revolutions does the engine make during this
time?

Name the law on which hydraulic machines work. State this law. A
liquid is filled in a
container. Does the pressure of this liquid depend on the shape of the container? O
GG-H(Section-C)

State law of equipartition of energy. Using it find the ratio of specific heat
capacities for_
monoatomic gases.

Discuss the normal modes of oscillations of a stretched string

clamped at both the ends.
344OR

Discuss the normal modes of oscillations in an air column whOse one end is
opened at
other end is closed.

X-PHYSICS
 Y=3ti+ 2r°j+ sk

(a)
(b) t= 1s R vít) h1 fur

The position of a particle is given by

i=3ti +21j+ Sk
where t is in seconds and the coefficients have the proper units for r to be in metres.
(a) Find v(t) and a(t) of the particle
(b) Find magnitude of (t) at t =l s.

aiMaI -385 Jsm).

300°C

What is the temperature of the steel-copper junction in the steady state of the sys
shown in figure? Length of the steel rod = 15 cm, length of the copper rod = 10
temperature of the furnace = 300°C, temperature of other end = 0°C. The area of .3
section of the steel rod is twice tht of the copper rod. (Thermal conductivity of ste
50.2 J s-l m k';and of copper =385 Jsm k).
Insulating material As=2A
|Ice Box
(Sans ) 300°0 0

ksAs CT-T)
Steel Copper

ksAs CT7 X-PHY

So2x2Hex(o-1)
lo Xlo2
 3TfaT/OR

UE =1.70 x 105k
A hole is drilled in acopper sheet. The diameter of the hole is 4.24cm at 27°C. What is
the change in diameter of the hole when the sheet is heated to 227°C?
Coefficient of
linear expansion of copper = 1.70 x 10

Tu aaet
d=424 to c.
ti27%
b 227
A+2oD,:
chage
moern
-/3 j-21/3
z4-24xToxdoD 2
axss Rst
What do you mean by mþment of inertia of a body? Find the moment of inertia of the
system rotating about given axis.

(/3
ie2//3

gG-Z (Section-D)

Find the expression for kinetic energy and potential energy of a particle in simple
harmonic motion. Draw the graph for both the energies with displacement
3440R

XI-PHYSICS
 3T

m
k k

(a)

(b)

(c)

Two identical springs of spring constant k each are attached to a block of mass man,
a fixed supports as shown in figure.
1m
k k

(a) Show that when mass is displaced from its equilibrium position on either si
executes a simple harmonic motion.

(b) Find period of oscillations.

Keeping mass of block constant, if spring constants of both springs are dout
(c)
find new period of oscillation.

limitation.
State andprove Bernoulli's principle. Write its one
4

G
m-Cof}sa ntoVIs costy -0emy
Define terminal velocity. Drive expression for it. Which one has greater termnal elo
larger rain drop or smaller?
uyhon body ateivomil elr bey
U+F= W

X-PHYs

2r e]
(a)

(b)

(c)

projectile is thrown at angle with X-axis with velocity u. Find:

A
(a) Equation of path of projectile
(b) Time of flight of projectile
(c) Maximum height of projectile
34/OR

(a)

Acircular raretrack of radius r is banked at angle 0. The coefficient of friction between

wheels of race car and the road is u.

(a) Derive the expression for maximum permissible speed to avoid slipping.
(b) Derive the expression for optimumn speed of the race car to avoid wear and tear on
its tyres.
dG-T
(Section-E)

13
XI-PHYSICS

.
 Uniform circular motion
When an object follow a circular path at a constant speed, the motion of the object:

velocity of the object is changing

incalled uniformthecircular
direction, objectmotion. Sincethe
continuougly
undergoes acceleration. This acceleration is always di:rected
towards the centre of the circle.

Answer the following questions :

(i)
path?
What is the direction of velocity at a point on this

(ii)

Name the acceleration in object on this path.

(ii)
Define this acceleration.

34T/OR

false :
Read each statement below carefully and state if it is true or

(a)

The acceleration vector of a particle in uniform circular motion averaged over

cycle is a null vector.

(b)
Displacement in a cycle is zero.

XLPHYSIC
|4
y

Planetary motion
proposed by Ptolemy about 2000 years
The earliest recorded model for planetary motions sun and the planets,
celestial objects, stars, the
ago was a geocentric model in which all
were also advanced by Indian astronomers
all revolved around the earth. Similar theories was the centre
elegant model in which the sun
some 400 years later. However, a more
'heliocentric' model - was already mentioned by
around which the planets revolved - the
Aryabhata (S" century AD) in his treatise.
observations of the planets
Tycho Brache (1546-1601) spent his entire life time recording
(1571-1640) compiled data and
with the naked eye. His assistant Johannes Kepler
name of Kepler's laws.
analysed and extract from data three elegant laws now go by the

Answer the following questions :

()

On which basic principle of Physics is the Kepler's second law based?

SI 15 XI-PHYSICS
 Which law of Kepler corresponds to Newton's law of gravity?

State Kepler's third law.

31c/OR

Why a planet has different speed at different positions in its orbit around the sud

|d

3d

|i b

X-PHISICS
16