AHSEC HS 2nd Year Question Paper 2023 Physics

ASSAM BOARD
QUESTION
PAPER
2023

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Total 11unber
33T PHYS of pages - 16

2023

PHYSICS
(Theory)
Full Marks : 70
Pass Marks.: 21

Time :Three hours

The figures in the nargin indicate full marks
for the questions.

O. No. 1 carries 1 nark ench 1x08 08

0. No. 2 carries 2 1marks each 2x10 = 20

3x 09 = 27
Q. No. 3carries 3 narks enclt
5x 03 = 15
0. No. 4 carries 5 1arks eaclh
Total = 70

Contd.

1x8=8
directed:
1. Answer any eight questions from the Iolowing as

off
a) We hear a crackle when we
take Our synthetic cloths or sweater
of
particularly in dry season. It nappens because(Fill in lhe blanks)

( JRg A)

{b) The mathematical expression given
below is knowWn as
(Fill in the blank)
principle.
1
4Eo i=2 1i

n
41
4nEo i=2 1i
Which of the
() Tworesistors of equal values are connected in parallel. are
combination
following options is correct if the two ends?of the 1
connected across the terminals of a battery
() i, =i, (currents flowing through the resistors)
(ii) V, = V, (potential differences across each resistors)
(iii) Both of the above are correct.

()

(ii) V, = V, (14* yoR ArO)

33T PHYS |2]

(d) The force acting in between two
parallel wires of length 10nz carrying
Current of 1A through each of therm
will be
and placed ln1 apart in vacuum
(Fill in the blank)
1

(e) The mÍst important prediction to emerge
is
from Maxwell's equations
1
(1) eddy current
iY electromagnetic waves
(iii) displacement current
(Choose the correct option)

(i)

() A plane mirror lies on x-y plane. If the
incident ray is on y-z plane
then the reflected ray and the normal will lie on 1
X-y and y-z plane
(i) y-z and z-x plane
(iii) z-x and x-y plane
(Choose the correct option)

(i)
(1) y-z Z-X 9G

33T PHYS
[3] Contd.

(g) Mirage is an optical phenomenon related to 1
() scattering
(11) total internal reflection
(ii) total internal refraction (Choose the correct option)

(1) If 2, and A, be the wavelength o de Broglie waves for a proton and
an alpha particle then which of the tollowing is correct ? 1

)
(ii)
< ha (Cho0se the correct option)

() The term d, = is called 1
nme
() impact parameter
(ii) Bohr radius
(ii) activity (Choose the correct option)

nme

(i)

(i) frgu

33T PHYS [4]

() The space-charge region on both sides of a p-n junction is known as
1
(i) cut-off region
(ii) active region
(iti) depletion region (Choose the correct option)

()
(ii)

(k) If Ec, Esi and E be the energy gaps between CB and VB of
C(diamond), Si and Ge then which of the following is correct ? 1

A7 Ec» Es E, A C(â), Si Aa Ge CB VB

() Eç > E_ > Ece
(ii) Ec <Esi < EGe
(Choose the correct option)
(ii) Eç >Es =Ece.

as directed: 2x10=20
2. Answer any ten questions from the following

Write an alternate unit of
(a) ) What is the SI unit of electric field? 1+1-2
it if any.

OR/ a

the force between two small charged spheres having
(ii) Calculate x 10-7Cplaced 30 cmapart in air.
charges of +1 x10-%Cand -1 2

Contd.
33T PHYS [5]

0 +1x 10-7C -1x 10-7C

(b) () Name the too forces with their nature acting between
hx4=2two
protons.

OR/ A0
(i1) Find out the incorrect options from the following:
LA) Inside a conductor, electrostatic field can never be 1+1=2
(B) At the surface of acharged conductor, electrostaticzero.
field
must be normal to the surtace at every point.
C) The interior of aconductor can have excess
charge in the
static situation.

(c) ) State Kirchhoff's laws in current
electricity.

OR / WAI
(ii) Name the electrical device
which is similar to one use of
potentiometer. What does the following expression ? mean
1+1-2

33T PHYS
[6]

(a) (9 Establish the expression for current eiller I, or l, which are
flowing throuek the resistors R and R, respectively and
Connected in Parallel to a cell of e.m.f. Eand total curent is I
(ie. I,+l,). 2

OR/
(ii) Match the following and rewrite: hx4=2

ta) = quB sin 9
(2) F (b) = mu/qB

(3) r
Idl xY
(c) 47 r

(4) dB a) -qlF) +öxBF))
(e) () Calculate the value of #o/4n and write its unit. 1/2+h=2

OR/ aT

(i1) A current of 0-40 A is flowing through a coil of radius 8-0 cm
and having 100 turns. Find the magnetic field at its centre. 2

() ) Derive the expression for motional emf as [ =Blu. Where the
symbols have their usual meaning. 2

33T PHYS [7] Contd.

OR/ W

(1) A current of 4-0Ais flowing in a coil. If the current suddenly
falls to 0-0A in 0-1s an average enf of 200 Vis induced. Calculate
the coeficient of self induction of the coil.

8) The household line voltage of 220V is an value with a
peak voltage of 311 V(Fillintle bank). Establish an expression relating
the terms P, V, and R. 1+1=2

I5 A|a311 V(R )| P, V, UERatD4O ADI

(4) () A tank is filled with water to a height of 12-5 cn. The apparent
depth of needle lying at the bottom of the tank is measured by
a microscope to be 9.4 cm. What is the refractive index of water ?
2

OR /W
(i) Draw aray diagram to make someone understand how a virtual
and many times magnified image of an object is formed in a
compound microscope. 2

33T PHYS [81

() Aplane wavefront is travelling from lighter medium 1to denser
2through the interface of medium
mediums 1 and2 with velocities v, and u, and
you know well that sin i/ sinr= V, / ,
of incidence and refraction, If n, and n, bewhere i and r are the angles
the refractive indices of the
mediums then derive Snell's law. 2

Asini| sin r=
V/V2

() ) The Lyman series is in the .region, but Paschen and
Brackett series are in the region. 1+1-2
(Fill in the blanks)

OR/ a
(11) Explain in brief the type of energy states of an electron above
E=0.

Calculate the energy equivalent of 1 kg of a substance. 2

OR/ WT
(ii) Discuss conductor and insulator in terms of energy gap. 2

() Using a p-n junction diode draw a circuit diagram of ahalf wave
rectifier showing input and output waveform. 1+1=2

33T PHYS Contd.

equilibrium? How doesthe situation
() What do you mean bythermal in terms of electron and hole
is mathematically expressed concentration ? 1+1=2
COncentrations and intrinsic carrier

dipole with dipole
3. (a) ) What is an electric dipole An electric with the direction of a
moment 4x 10-cm is aligned at 30°
NC-1. Calculate the
uniform electric field of magnitude 5 x 10+ 1+2=3
magnitude of the torque.

OR / at

(ii) Show th¡t the energy stored in a charged capacitor is E = Y CV²,
where the symbols have their usual meaning. 3

(b) ) What is a Wheatstone bridge? Establish the mathematical form
of it. 1+2=3

OR /a

(ii) You have been given n resistors each of value R. How will you
combine them to get (i) maximum and (ii) minimum effective
resistance? Mention the values in each case. Find the ratio of
maximum to minimum values of resistance. 2x4+1=3

33T PHYS [10]

(c) ) Write afew lines on any two of magnetic
declination, magnetic
inclination(ie. magnetic ip), horizontal component, and vertical
Component. 1/2+1=3

OR/ A0
(i) Two long and parallel straight conductors Aand Ba
CuIrents of 8-0 A and 5-0Ain the same direction. Aareandcarrying
B are
separated by a distance of 4-0 cm. Calculate the force on a 10 cm
portion of wire A. 3

5i|9 REI A B f uR AGR JAA 4-0cml A

(d) ) Describe any one experiment where gerneration of induced emf
can be clearly demonstrated. 3

OR /R
(ii) Explain any one advantage of using eddy current in (a)
magnetic
braking in trains, (b) electromagnetic damping, and (c) induction
furnace. 3

33T PHYS
[11] Contd.

between an Ac generator and a motor.
(e) (i) Mention one difference generator and indicate there («) the
of AC
Draw a neat diagram axle, and (d) the carbon brasses.
rings, (c) the
coil, (b) the slip 1+4x/2=3

(b) a fRR, (c) 4A1, (d)
OR /Weat

solenoid having 15 turns per cm has a small loop of area
Along
(1)
inside the solenoid normal to its axis. If the
2 sq.cm placed the
of current in the solenoId is 2-0Ain 0-1s, find
change 3
induced enf in the loop.

and find the
Write the mirror equation. Define magnification
expression for magnification m from the mirror equation. 1+1+1=3

1014 Hz. If a light
(g) The threshold frequency for a certain metal is 3.3 x
calculate
of frequency 8.2 x 10*Hz is incident on that particular metal, 3
the cutoff voltage for photoelectric emission.
QD 194 s F * 3.3 x 1014 Hz| 190K 943 8.2 x 1014Hz

33T PHYS [12]

(h) () The radius Of the innermost electron orbit of a
is
5-3×]0-11, m. Calculate the radii of n=2 andhydrogen atom
n=3 orbits.
Given, r, n/m)(h /2n (4na/e') 2+1=3

5:3×\0-l1 ms n=2 l% n=3 GF

OR/ I
(i) What do you mean by radioactive decay? Mention the types of
radioactive decay. 12+1h=3

() () Draw, a neat circuit diagram to show a Zener diode acting as a
Cvoltage regulator. What should be the approximate voltage
rating of the diode used in relation to the required output
voltage ? 2+1-3

OR/T

(ii) Write a few lines on any one of the following with
Use:
purpose of
2+1=3

(1) Light emitting diodes
(2) Photovoltaic devices

(1) ( (LED)

33T PHYS [131 Contd.

4. (a) () What do you understand by capac1tance of a capacitor ? Write
and picofarad (pF), Obtain an
the relation between farad(F)
parallel plate air capacitor. Do you
expression for capacity of a effects on capacity of a
think that dielectric has important 1+2+3+Y2=5
condenser ?

OR/QA

() R, R and Ra are three resistors. Parallel combination of R and
R, is connected to R in series. If V be the potential difference
between the end points of the mixed combination, then show
that the total current flowing in the circuit is 5

I=
V(R, +Rg)
RR, +RR +RzRg

V(R, +R3)
RR, +R, + R,R,

(b) () Derive the expression for magnetic field at a point on the axis
of acircular current loop. Also find the magnetic field at the
centre of the loop. 4+1=5

33T PHYS [14]

()(ii) OR/ 40
Derimatveerialtheof
ftheol owiprism,
ng expression for
where the refractive index of the
meaning: symbols have their usual
sin(A +D, )/2)
The sin[A/2
For an refirnacictidvente index of glass in the form of a
ray of light the prism is unknown.
found to be 40° angle of minimum deviation is
the prism if .Calculate the refractive index of the material of
the angle
of prism is measured to be 60. 3+2=5

ngi =Sin|(A+ D, )/2]
sin A/2

(c) (1) Discuss the phenomena of diffraction
by drawing a neat produced by a single slit
diagram. 1+4=5

OR/ Ra
(11) Write the mass-energy
relation ? Calculate the equivalent relation. Who discovered the
mass equivalent of 9x|0$]energy. Does
the relation have any
experimental proof? 1+1+2+1=5

33T PHYS [15]