Malayalam and English-Physics

1319 (NP)

!1319NPPhysics!

PART - III

nTf]WwLNñU ^{/ PHYSICS}

(

ospLtU, CUYæ}xV nLxLÍqeU

yopkq]i]

oe]¨P¡

kqoLvi] oL¡¨V

Time Allowed : 2.30 Hours ] [Maximum Marks : 70

j]¡SÇw°¥ :

S\Lh|¨asLô]Rs A\ÿa]pORa YOej]svLqU DrÕOvqO¾OW.

IRÍË]sOU SkLqLpÜWtORºË]¤ zL¥ yPÕ¡RRvyrOoLp]

mÌRÕaOW.

(2)

IuOfOvLjOU Aa]vqp]aOvLjOU WrOSÕL j}sSpL j]r¾]sOç ox]oLNfU DkSpLY]¨OW

\]Nf°¥ vqàOvL¢ Rk¢y]¤

DkSpLY]¨LU.

Instructions : (1) Check the question paper for fairness of printing. If there is any lack of fairness, inform the Hall Supervisor immediately.

(2) Use Blue or Black ink to write and underline and pencil to draw diagrams.

nLYU &

WOr]ÕV :

IsæL S\Lh|°¥¨OU D¾qU j¤WOW.

(ii)

fÐ]q]¨OÐ jLsV D¾q°t]¤j]ÐV JãvOU SpL^]\ÿ D¾qU f]qR´aO¾VV D¾qvOU KLkVVx¢ SWLcOU IuOfOW.

Note : (i) Answer all the questions.

(ii) Choose the most appropriate answer from the given four alternatives and write the option code and the corresponding answer.

A

Rr^]ð¡ jUm¡

1.

CsNW›]WV RRcSkLt]R£ SWNξ]¤ j]ÐOU Af]R£ AÞÿOfºV SqXRàLÕU

AWs¾]sOç RRvh|Of f}NvfpORa AtvLeV

CsNW›]WV RRcSkLt]R£

SWNξ]¤ j]ÐOU Af]R£ nPoi| SqXpVR¨LÕU ASf RRvh|Of f}NvfL oPs|U

E

pOç m]ÎOv]Ss¨Oç AWsoLeVV

(a) r

2 (b) ¹₃

r

(3) (c)

1

r(2)3 (d) ¹₃

r (2)

The magnitude of electric intensity at a distance ‘r’ from the centre of an electric dipole along its axial line is E. The distance of the point from the centre of the electric dipole along its equatorial line at which the electric intensity has the same value E is :

(a) r

2 (b) ¹₃

r

(3) (c)

1

r(2)3 (d) ¹₃

r (2)

2.

KqO RRySWæLSNaLe]¤ SNkLSŸLeOWtORapOU

We°tORapOU W]qeU v]^pWqoLp] f~q]fRÕaO¾OÐO. yLiLqe WLÍ]W o¼s¾]R£ j]q¨]¤

RRySWæLSNaLe]¤ NkSpLY]¨OÐO Af]jL¤ SNkLSŸLe]jO

We°¥¨OU KSq Wr°¤ WLsoLeV

(a) 1 : 4 (b) 4 : 1 (c) 1 : 2 (d) 2 : 1

A beam of protons and α-particles are successively accelerated in a cyclotron. The ratio of the normal magnetic field to be applied to the cyclotron so that protons and α-particles have the same period of rotation is :

(a) 1 : 4 (b) 4 : 1 (c) 1 : 2 (d) 2 : 1

3.

Src]SpL BW›}vV khL¡À°tORa fOs| Atv]sOç qºV yLÒ]tOW¥ DºV.

8

oe]¨Pr]jOSwxU

pORa

&LU nLYvOU

pORa

&LU nLYvOU ƒp]¨Lf]q]¨OÐO.

pORapOU

pORapOU A¡ÈLpOyV WLs°tORa AjOkLfoLeV

(a) 1 : 4 (b) 4 : 1 (c) 1 : 2 (d) 2 : 1

Two samples of radioactive substances have the same quantity. 1 th

16 portion of A and 1

th

256 portion of B remain undecayed after 8 hours. The ratio of half life periods of A and B is :

(a) 1 : 4 (b) 4 : 1 (c) 1 : 2 (d) 2 : 1

4.

KqO NkWLw&yUSvhj Nkfs¾]R£ RNfSxL¥cV BvQ¾]

BeV.

fÐ]q]¨OÐ Jf]jLeV ASf Nkfs¾]¤ j]ÐOU RRvh|OfNkWLw Dá²jU DºL¨L¢ Wu]pOÐfV?

(a)

rPm]&Ssy¡ NkWLwU

Ssy¡ NkWLwU

(c)

RySjL¦ o]Ф NkWLwU

qº]jOU

The threshold frequency of a photo-sensitive surface is 5×10¹⁴ Hz. Then which of the following can produce photoelectric emission from the same surface ?

(a) Ruby - Laser light (b) He - Ne Laser light (c) Xenon flash light (d) Both (a) and (b)

5.

fÐ]q]¨OÐvp]¤ c].y]. WaÐOSkLWL¢ AjOvh]¨L¾ DkWqe°¥

JfLeV?

(a)

Rry]ð¡

WÕLy]ã¡

(c)

C¢cW›¡

CvRpsæLU

Which of the following devices does not allow d.c. to pass through ?

(a) resistor (b) capacitor

(c) inductor (d) all the above

6.

KqO

&We¾]jV

RoLo£oOç KqO j|PWæ]py]R£ JãvOU AaOS¾¨V I¾LvOÐ AWsU

. ASf j|PWæ]py]jaOS¾àV

RoLo£U RWLºV

&WeU yµq]¨OSÒLuOç JãvOU AaO¾ hPqoLp]q]¨OU

(a) 4r0 (b) r⁰

4 (c) 2r0 (d) r⁰

2

The distance of closest approach of an α-particle reaching a nucleus with momentum

‘p’ is r0. When the α-particle travels towards the same nucleus with momentum p 2, the distance of closest approach will be :

(a) 4r0 (b) r⁰

4 (c) 2r0 (d) r⁰

2

7.

mL¢cV v]cV¾V

BReË]¤ p‚õ]R£ cm]¥ yæ]ãV kq}ƒe¾]¤ Bh| CqOº mL¢cOU BrLoR¾ Rft]ÞÿoOç mL¢cOU fÚ]sOç AWsoLeV

(a) 1

5

2 β (b) 6 β (c) 11 β (d) 5 β

If β is the bandwidth, in Young’s double slit experiment, the distance between the first dark band and sixth bright band is :

(a) 1

5

2 β (b) 6 β (c) 11 β (d) 5 β

8.

mPt]p¢ m}^Ye]f j]po°¥ AjOyq]ÞÿV

IÐ yovLW|¾]jV yooLeV :

(a) B (b) A (c) A (d) AB

According to the laws of Boolean algebra, the expression (A+AB) is equal to :

(a) B (b) A (c) A (d) AB

9.

KqO NkSf|W AWs¾]¤ vLpOv]¤ vÞÿ]q]¨OÐ SkLp]£V ÞL¡²OWtLeV

pOU

6 µC

pOU.

p]¤

àOç ms¾]R£ kq]oLeU

p]¤

àOç ms¾]R£ kq]oLeU

IË]¤

BeV

(a) 1 : 1 (b) 36 : 1 (c) 1 : 6 (d) 6 : 1

Point charges 1 µC and 6 µC are placed in air at a certain distance apart. The magnitude of the force on 1 µC by 6 µC is F1. The magnitude of the force on 6 µC by 1 µC is F2. Then F1 : F2 is :

(a) 1 : 1 (b) 36 : 1 (c) 1 : 6 (d) 6 : 1

10.

DÐf BvQ¾] fqUY°¥

k]ÍOaqOÐO.

(a)

ASpLe}Wqe NkyqeU

(b)

nPo]pORa vNWf

(c)

frj]qÕ]Rs fqUY NkyqeU

(d)

v}ƒe h]wp]Rs SqX

High frequency waves follow : (a) ionospheric propagation (b) the curvature of the earth (c) the ground wave propagation (d) the line of sight direction

11.

KqO RRzNc^¢ BãU

DT¡²U BY]qeU RÞáOSÒL¥ Af]R£ B¢YOsL¡

RoLo£¾]R£ oLãoLeV

(a) 4.14×10⁻¹⁵ Js (b) 0.525×10⁻³⁴ Js (c) 1.05×10⁻³⁴ Js (d) 2.1×10⁻³⁴ Js

When a hydrogen atom absorbs an energy of 10.2 eV, the change in its angular momentum is :

(a) 4.14×10⁻¹⁵ Js (b) 0.525×10⁻³⁴ Js (c) 1.05×10⁻³⁴ Js (d) 2.1×10⁻³⁴ Js

12.

AvsLRµ SNm¨VcT¦ NkLgo]WoLp] Bèp]¨OÐ Nkf]nLyoLeV

(a)

ScLk]‚V

kOjyUSpL^jU

(c)

WPŸ]p]a]¨¤

ASpLe}WqeU

Avalanche breakdown is primarily dependent on the phenomenon of :

(a) doping (b) recombination

(c) collision (d) ionisation

13.

KqO y¡W|PŸ]Rs Nkf]iLqL RRvh|Of]pORa yovLW|U RWLaO¾]q]¨OÐfV

 

 

 

10 sin 100 t 6 π

= π +

i

IÐLeV. RRvh|Of] Af]R£ Bh| kqoLvi]p]¤

p]¤

I¾OÐfV

(a) 1

s

600 (b) 1

s

50 (c) 1

s

100 (d) 1

s 300

The alternating current in a circuit is given by the equation  

 

 

10 sin 100 t 6 π

= π +

i . The

current attains its first maximum at t is :

(a) 1

s

600 (b) 1

s

50 (c) 1

s

100 (d) 1

s 300

14.

KqO RRvh|Of m¥m]¤

IÐV AapLtRÕaO¾]p]q]¨OÐO.

oLp] AfV mÌ]Õ]¨OSÒL¥ Af]R£ kvrLeV

(a) 200 W (b) 173.2 W (c) 50 W (d) 25 W

An electric bulb is marked 220 V, 100 W. When it is connected across 110 V, its power is :

(a) 200 W (b) 173.2 W (c) 50 W (d) 25 W

15.

KqO oPv]‚V SWLp]¤ YL¤vSjLo}ãr]¤ fP¨]p]aLjLp] DkSpLY]¨OÐfV SlLóryV&SNmL¦yV WÒ]pLeV, WLqeU Af]jV

DºV

(a)

pPe]ãV f]q]v]Rs vs]p S^La]

(b)

pPe]ãV f]q]v]Rs RÞr]p S^La]

(c)

Dp¡Ð RRvh|OfvLzW w©]

(d)

Dp¡Ð Nkf]SqLi w©]

Phosphor-bronze wire is used for suspension in a moving coil galvanometer, because it has :

(a) large couple per unit twist (b) small couple per unit twist (c) high conductivity

(d) high resistivity

nLYU &

SÞLh|U

j]¡mÌoLpOU D¥RÕaO¾] JRfË]sOU BrV SÞLh|°¥¨V D¾qRouOfOW.

Answer any six questions and question number 24 is compulsory.

16.

CsNW›]WV RRcSkL¥ RoLo£V j]¡vÞ]¨OW. Af]R£ pPe]ãV j¤WOW.

Define electric dipole moment. Give its unit.

17.

KLU j]poU j]¡vÞ]¨OW.

State Ohm’s Law.

18.

Rk¤ã]p¡ SWLpl]x£V j]¡vÞ]¨OW.

Define Peltier Coefficient.

19.

c}&SoL¡Y¢yV y]ÈLÍU NkñLv]¨OW.

State De-Morgan’s theorems.

20.

C¢NlLRrcV qwÜ]WtORa DkSpLY°¥ IuOfOW.

Write the uses of infra-red rays.

21.

Ssyr]R£ y~nLv°¥ IRÍsæLU?

What are the characteristics of laser ?

22. K

Yf]SWL¡²oOç KqO j|PSNaLe]R£ c}&SNmLYæ] fqUYRRh¡Z|U

BeV. Af]R£

Yf]SWL¡²U

BWOSÒL¥ B j|PSNaLe]R£ c}&SNmLYæ] fqUYRRh¡Z|U IÍV?

The de-Broglie wavelength of a neutron of kinetic energy K is λ. When its kinetic energy is 4 K, what is the de-Broglie wavelength of the neutron ?

6x2=12

23.

W|Pq] j]¡vÞ]¨OW.

Define curie.

24.

KqO oLfQWL NaL¢SóLor]R£ NkLgo]W ÞOãOWtORa I¹U

DU h~}f]p ÞOãOW¥

2000

DU BeV.

¤ Ry¨¢cr]p]¤ j]ÐOç KTŸVkOŸV kv¡

BReË]¤

NkLgo]W SWLp]s]Rs RRvh|Of]pOU SvL¥SŸ^OU We¨L¨OW.

The number of turns in the primary of an ideal transformer is 400 and that in the secondary is 2000. If the output power from the secondary at 1000 V is 10 kW then calculate the voltage and current in the primary coil.

nLYU &

SÞLh|U

j]¡mÌoLpOU D¥RÕaO¾] JRfË]sOU BrV SÞLh|°¥¨V D¾qRouOfOW.

Answer any six questions and question number 33 is compulsory.

25.

RRvh|Of ms SqXWtORa yv]SwxfW¥ IuOfOW.

Write the properties of electric lines of forces.

26.

Ry¨£]¤

Nkf]SqLiW¾]¤ DºLWOÐ fLkU

BeV. fÐ]q]¨OÐ RRvh|Of y¡W|PŸ]Rs

Nkf]SqLiW¾]¤ Ry¨£]¤ DºLWOÐ fLkU We¨L¨OW.

The heat developed across 6 Ω resistor per second is 50 J. Calculate the heat developed per second across 2 Ω resistor in the given electric circuit.

27.

WLÍ]W SsLr£VyV ms¾]R£ NkSf|W yv]SwxfW¥ IuOfOW.

Write the special features of Magnetic Lorentz force.

6x3=18

28.

KqO C¢cW›rOoLp] mÌRÕŸ]q]¨OÐ DT¡²¾]R£ yovLW|U sn|oL¨OW.

Obtain an expression for the energy associated with an inductor.

29.

BvQ¾] SoLcOSsx¢ v]wh}Wq]¨OW.

Explain frequency modulation.

30.

NmLY]R£ j]poU NkñLv]ÞÿV jaÕ]sL¨OW.

State and obtain Bragg’s Law.

31.

RRh¡Z| ySËLÞU v]wh}Wq]¨OW.

Explain length contraction.

32.

qºV Src]SpL BW›}vV oPsW°tORa A¡ÈLpOôV pgLNWoU

oe]¨PrOU

16

oe]¨PrOoLeV. JfV yop¾OU Src]SpL BW›}vV khL¡À°tORa Atv]R£

AjOkLfU

BWORoË]¤

h]vy¾]jV SwxU jw]¨L¾ nLY°tORa AjOkLfU IÍLp]q]¨OU?

Half lives of two radioactive elements are 12 hrs and 16 hrs respectively. If at any instant, the ratio of the amounts of radioactive substances is 2 : 1, then after 2 days, what will be the ratio of the undecayed portions ?

33.

p‚]R£ cm]¤ yæ]ãV kq}ƒe¾]¤ f}NvfpORa AjOkLfU

Dç qºV RWLRzr£V vñO¨¥ C£¡Rlr¢yV Nl]¢^yV Ds×Lh]Õ]¨OÐO. WOrîfOU WPa]pfOoLp f}NvfWtORa AjOkLfU We¨L¨OW.

In Young’s double slit experiment two coherent sources of intensity ratio of 64 : 1, produce interference fringes. Calculate the ratio of maximum and minimum intensities.

nLYU &

IsæL SÞLh|°¥¨OU D¾qRouOfOW.

Answer all the questions.

34. (a)

AÞÿOfºV SqXp]Rs KqO m]ÎOv]Rs RRvh|Of RRcSkL¥ oPsoOç RRvh|Of o¼s¾]R£ f}NvfpORa yovLW|U AjOoLj]¨OW.

ARsæË]¤

(b)

RRvh|Of] vz]¨OÐ AjÍoLp] j}toOç Sj¡SqXL ÞLsW¾]Rs KqO m]ÎOv]sOç WLÍ]W C¢cƒR£ yovLW|U sn|oL¨OW.

(a) Derive an expression for electric field intensity due to an electric dipole at a point on its axial line.

OR

(b) Obtain an expression for the magnetic induction at a point due to an infinitely long straight conductor carrying current.

35. (a)

lLqRcpORa CsSNW›Ls]y]y]R£ qºLU j]poU NkñLv]¨OW.

kq}ƒe¾]sPRa AfV I°Rj yo¡g]¨LU?

ARsæË]¤

(b)

qLoR£ NkWLw NkW}¡¹f v]wh}Wq]¨OW.

(a) State Faraday’s II law of electrolysis. How is it verified experimentally ? OR

(b) Explain Raman Scattering of light.

36. (a)

KqO SWLp]s]¤

DºLWOÐ q}f] Af]R£ WLÍ]W o¼s¾]R£

h]wàjOyq]ÞÿV v]j|LyU oLãOÐORvÐV y]ÈLÍ yz]fU Þ¡Þÿ RÞáOW.

ARsæË]¤

(b)

zLlV SvvV cSpLcV RrW›]lpr]R£ Nkv¡¾jU v]wh}Wq]¨OW.

(a) Discuss with theory the method of inducing emf in a coil by changing its orientation with respect to the direction of the magnetic field.

OR

(b) Explain the working of a half wave diode rectifier.

37. (a)

RRzNc^¢ Bã¾]R£ Ry×NW›¤ Sèe] v]wh}Wq]¨OW. (Þ]NfU Bvw|o]sæ) ARsæË]¤

(b)

vQ¾]pOç Þ]Nf¾]R£ yzLpS¾LRa

Src]SpL NaL¢yVo]ãr]R£

Nkv¡¾jU v]wh}Wq]¨OW.

(a) Explain the spectral series of hydrogen atom. (Diagram not necessary) OR

(b) Explain the function of AM radio transmitter with neat block diagram.

38. (a)

KqO Y}Y¡&oOç¡ WTºr]R£ j]¡ÚLevOU Nkv¡¾jvOU v]wh}Wq]¨OW.

ARsæË]¤

(b)

NkWLw Dá²j Rysæ]R£ Nkv¡¾jU v]wh}Wq]¨OW. RRvh|OfNkWLw RysæOWtORa JRfË]sOU qºV NkSpLY°¥ IuOfOW.

(a) Explain the construction and working of a Geiger-Muller Counter.

OR

(b) Explain the working of photo emissive cell. Write any two applications of photoelectric cells.

- o O o -