Assam Board Class 11 Question Paper 2023 Physics

ASSAM BOARD
QUESTION
PAPER
2023

Download PDF

Total No. of Printed Pages-15
23E-PHYS

2023

PHYSICS

(Theory)
Full Marks: 70
Pass Marks : 21

Time: 3 hours

The figures in the margin indicate full marks for the questions

ALLOTMENT OF MARKS

0. No. 1l carries Imark each 1x8 = 8

Q. No. 2 carries 2 markS each 2x12 = 24

0. No. 3 carries 3 markS each 3×6 = 18

0. No. 4 carries 5 marks each 5x4 = 20

Total = 70

/134 [Contd.

(2 )

questions .
1. Answer any eight of the 10llowing 1x8=8

(a) Fill up the blank

A screw gauge and a spherometer can be used to
to
measure lengths as less as m.

(b) How many significant figures are there in the
number 0-002308?

(c) In the case of negative acceleration, which of initial
velocity and final velocity is greater?

(d) If the resultant of i and j has magnitude 2, then
what is the angle made by the resultant with ?

(e) Name the projectile motion in which range does not
depend on initial. velocity.

What fraction of coefficient of superficial expansion
becomes equal to coefficient of volume expansiorn?

(3 )

(g) What is the SI unit of scalar product of the vector
quantities-force and velocity?

(h) At what position, velocity of a particle executing simple
harmonic motion will be maximum?

() State Boltzmann's law of
equipartition o1 energy.

6) When does resonance occur?

2. (a) Draw the position-time graph of an object moving
with () positive velocity and (i) negative velocity. 1+1=2

Or/ e I

The position of an object moving along x-axis is
given by x=8-5+2-5t. Calculate its average velocity
between t=0 s and t=2-0 s. 2

/134 | Contd.

(4 )

by equality of vectors? If Áis
(b) What do you mean equal to 3Á
then draw a vector which is
vector, 1+1=2

Or / AI

inclined projectile is
You know that range of an show
expressed as given below. From the expression,
vertically projected body
that the range in case of
1s zero:

R=. vÕ sin 20,

2
where the symbols have their usual meanings.

R=
vo sin 2 o

(c) Aristotelian law of motion may be stated as
"An external force is required to keep a body in
motion". Explain whether there is any flaw in it. 2

(5 )
Or /yA1

It is well-known to us that Newton's second law of
motion is stated mathematically as given belowW:
F= kma
Define k and also 1 newton force from it. 1+1=2

F = kmna

(a) An object of mass 1g falling from a height 1 km hits
the ground with a speed of 50 m s. Calculate the
change in kinetic energy. 2

1g Abi 8 1km tug I 50 m s A R UTDE

Or/ qAI

Express power as the product of force and velocity.

(e) Define a rigid body and centre of mass of a rigid body.
1+1=2

Or/ RI

A body is on y-axis, at a distance r from the origin.
If a force F acts on the body along a direction making
an angle with the axis, then write the magnitude
of moment of force acting on the body and its
dimensional formula. 1+1=2

/134 [Contd.

(6 )

/n Fill up the blanks mth the words 'geostationary
satellites' and polar satellites ax4=2
are
(i) INSAT group of satellites
(ti) are used for environmental studies.
(iti) revolve at 35800 km height.
(tv) are used for telecommunication.

i) INSAT CN GURTYR

(üi) 35800 km twus 1f* fRI AI
(iu)
Or/ AI

If the kinetic and potential energies of an orbiting
satellite of mass 1g are as given below, then find
the total energy of an orbiting satellite of mass m : 2

KE = GME and PE= GME
2(Rp + h) (Rp + h)

KE = GME lF PE= GME
2(Ry + h) (Ry + h)

(7)

(g) Calculate the pressure experienced by a swimmer at
a depth of 10 m of a lake. 2

Or / g41
Define angle of contact. Draw a diagram showing the
critical angle if a drop of water is placed on a clean
plastic plate. 1+1=2

(h) What do you mean by temperature? Convert O°C to
Fahrenheit scale of temperature. 1+1-2

Or / e I
What are heat capacity and specific heat capacity? 2

() Mention at least one difference between isothermal
and adiabatic processes. Write the ideal gas equation
for each. 1+½+h=2

Or/ gRI
When is a thermodynamic process said to be
reversible? Are the spontaneous processes of nature
reversible? 1+]=2

/134 |Contd.

(8 )

G) Define molar specific heat either at constant
nressure or constant volume. Write the ratio C, /C..
for a monatomic gas. 1+1=2

Or / eAI

What do you mean by mole? Find the number of
molecules in 44-8 litres of any gas. 1+1=2

(k) How is frequency related to time period of a vibrating
body? If the heartbeat of a healthy person is 75 per
minute, then find the heartbeat frequency. V2t12=2

Or / AI

Define simple harmonic motion. Draw two graphical
representations of SHMs vibrating in opposite phase.
(Hints Use one solid line and the other dotted line
for the graphs) 1+1=2

(9 )
harmonic motion
) Show that in the case of simple

k
2

Or / eT

A body oscillates with SHM according to the equation
(in SI units) x 5cos[2t +1], Calculate the frequency
and rewrite the expression for x at t=1·5s.
x= 5cos(2t +] (SI gFFI) T 4DR A RIE3 sfo

3. (a) Establish the equation x = V,t+at.
2
3

1
2

Or/ 1

Find the magnitude of the resultant of two vectors
and B, and angle between them.

(b) An object is on an inclined plane. If the body just
starts to slide down, then show that the angle of
inclination in that case is ax = tan , where the
symbols have their usual meanings. 3

/134 [Contd.

( 10 )

Or/AI
Amass of 4 kg rests on a
norizontal plane. The
gradually inclined to an angle of 15°, so thatplane is
it just
begins to slide down. What is the coefficient of static
friction between the object and the plane?

(c) Define moment of inertia of a
its unit? If 2 m is the rotating body. What is
translational kinetic energy of
a sphere, then what will be its
if it rotates about an axis rotational kinetic energy
with an angular velocity o?
1+%+1%=3
2

Or/qAI
Explain how acceleration due to gravity of
changes with altitude or depth (any one). the earth 3

(11 )

(d) What do you understand by elastic moduli? Name
them and write the mathematical expression oi any
one you like. 1+1%+h=3

Or / e1
It is very common to see a car lifting easily up in
servicing stations. Name the principle underlying this
achievement and give its word statement. Draw a neat
diagram of the device. Vat1+1h=3

(e) Find out the meaningful statement from the following :
() Agas in a given state has a certain amount of heat.
(1) Agas in a given state has a certain amount of work.
(üi) A certain amount of heat is supplied to a system.
Name the following expression and explain any two
terms of the following expression:
AQ= AU+AW
where the symbols have their usual meanings.
a+2%=3

|Contd.

( 12 )

AQ= U+ AWW

Or / AI

Derive the expression 10r pressure exerted by a gas
enclosed in a container. 3

mass m and
)A simple pendulum consisting of a bob ofposition
a thread of length L 1s in such a that
the thread makes an angle with the vertical.
If =-L(mg sin) 1s the torque about the support,
then show that the acceleration of the bob is
O = mgL 0. where I is the moment of inertia of the
I
system about the support. 3

mgl

Or/1

Show that in an isolated system, linear momentum or
angular momentum is conserved.

( 13 )
4. (a) Prove the law of cosines of vector addition. Also, derive
the law of sines. 3+2=5

Or / eAI

Discuss the motion of a car on a level road or on
a banked road. Find an
path.
expression for Umax On that
5

(b) What do you mean by one-dimensional collision?
Considering an inelastic collision, find out the loss
in kinetic energy on collision and
elastic collision, find out the velocitiesconsidering
an
of the bodies
after the collision.
1+2+2=5

Or/ yeI

Define surface tension and surface energy. What do
you mean by excess pressure inside a liquid drop or
bubble? Mention two factors on which excess
depends. pressure
1+1+1+1+1=5

[ Contd.

( 14 )

(c) A metal block of mass 0-20 kg at 150)°C is dropped
calorimeter of water equivalent 0·025 kg
in a copper 015 kg of water at 27 °C. If the final
and containing
temperature is 40°C, then calculate the specific heat
of the metal. 5

150 Cty5 I O20 kg qi Ag4 bAI 0-025 ke

Or/ AI

What do you mean by mean free path' of molecules
1
in a gas? You know that it is expressed as l=

What are n and d here? Draw a neat diagram to show
the volume swept by a molecule in time At in which
1%+1+1+1%=5
any molecule will collide with it.

1
l=
V2 rnd

(d) In the case of a particle executing simple harmonic
motion, derive the expressions for displacement,
velocity and acceleration. Draw graphs for any two.
1+1+1+1+1=5

15 )

Or / eTI

Write short notes on any two of the following : 2x2-5

f) Doppler effect

(ü) Degrees of freedom

(iti) Anomalous expansion of
water

(iv) Weightlessness

(u) Hooke's law

(vi) Physical quantity

/134 C23