55 1 1 Physics (Theory) SSO 1 C

8/20/2019 55 1 1 Physics (Theory) SSO 1 C

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55/1/1 1 [P.T.O.

¸ Öê »Ö ®ÖÓ. Roll No.

³ÖÖî ×ŸÖÛú ×¾Ö–ÖÖ®Ö (ÃÖî ¨ Ö×®ŸÖÛú)PHYSICS (Theory)

×®Ö¬ÖÖÔ ×¸ ŸÖ ÃÖ´ÖµÖ : 3 ‘ÖÓ ™ê ] [ †×¬ÖÛúŸÖ´Ö †Ó Ûú : 70

Time allowed : 3 hours ] [ Maximum Marks : 70

ÃÖÖ´ÖÖ®µÖ ×®Ö¤ì¿Ö ::::(i) ÃÖ³Öß ¯ÖÏ ¿®Ö †×®Ö¾ÖÖµÖÔ Æï … ‡ÃÖ ¯ÖÏ ¿®Ö-¯Ö¡Ö Öë Ûã ú»Ö 26 ¯ÖÏ¿®Ö Æï …

(ii) ‡ÃÖ ¯ÖÏ¿®Ö-¯Ö¡Ö Ûê ú 5 ³ÖÖÝÖ Æï : ÜÖÞ›- †, ÜÖÞ›- ²Ö, ÜÖÞ›- ÃÖ, ÜÖÞ›- ¤ †Öî ¸ ÜÖÞ›- µÖ …(iii) ÜÖÞ›- † ´Öë 5 ¯ÖÏ ¿®Ö Æï, ¯ÖÏŸµÖê Ûú ÛúÖ 1 †Ó Ûú Æî … ÜÖÞ›- ²Ö ´Öë 5 ¯ÖÏ ¿®Ö Æï, ¯ÖÏŸµÖê Ûú Ûê ú 2 †Ó Ûú Æï … ÜÖÞ›- ÃÖ ´Öë

12 ¯ ÖÏ ¿®Ö Æï, ¯ÖÏŸµÖê Ûú Ûê ú 3 †Ó Ûú Æï … ÜÖÞ›- ¤ ´Öë 4 †Ó Ûú ÛúÖ ‹Ûú ´Öæ »µÖÖ¬ÖÖ×¸ ŸÖ ¯ÖÏ¿®Ö Æî †Öî ÜÖÞ›- µÖ ´Öë 3

¯ÖÏ¿®Ö Æï, ¯ÖÏŸµÖê Ûú Ûê ú 5 †Ó Ûú Æï …

(iv) ¯ÖÏ¿®Ö-¯Ö¡Ö ´Öë ÃÖ´ÖÝÖÏ ¯Ö¸ ÛúÖê ‡Ô ×¾ÖÛú»¯Ö ®ÖÆ à Æî … ŸÖ£ÖÖ×¯Ö, ¤Öê †Ó ÛúÖë ¾ÖÖ»Öê ‹Ûú ¯ÖÏ ¿®Ö ´Öë , ŸÖß®Ö †Ó ÛúÖë ¾ÖÖ»Öê ‹Ûú

¯ÖÏ¿®Ö ´Öë †Öî ¸ ¯ÖÖÑ “Ö †Ó ÛúÖë ¾ÖÖ»Öê ŸÖß®ÖÖë ¯ÖÏ ¿®ÖÖë ´Öë †Ö®ŸÖ×¸ Ûú “ÖµÖ®Ö ¯ÖÏ ¤ Ö®Ö ×ÛúµÖÖ ÝÖµÖÖ Æî … ‹ê ÃÖê ¯ÖÏ ¿®ÖÖë ´Öë †Ö¯ÖÛúÖê

×¤ ‹ ÝÖ‹ “ÖµÖ®Ö Öë ÃÖê Ûê ú¾Ö»Ö ‹Ûú ¯ÖÏ¿®Ö Æ ß Ûú¸ ®ÖÖ Æî …

Series : SSO/1/C 55/1/1

• Ûé ÖµÖÖ •ÖÖÑ “Ö Û ü »Öë ×Û ‡ÃÖ ¯ÖÏ ¿®Ö-¯Ö¡Ö ´Öë ´Öã ×¦üŸÖ ¯Öé Âš 12 Æï …

• ¯ÖÏ ¿®Ö-¯Ö¡Ö ´Öë ¤üÖ×Æü®Öê ÆüÖ£Ö Û ß †Öê ¸ü ×¤ü‹ ÝÖ‹ Û Öê › ®Ö´²Ö¸ü Û Öê ”ûÖ¡Ö ˆ¢Ö¸ü-¯Öã ×ÃŸÖÛ Ö Ûê ´Öã ÜÖ-¯Öé Âš ¯Ö¸ü ×»ÖÜÖë …• Ûé ÖµÖÖ •ÖÖÑ “Ö Û ü »Öë ×Û ‡ÃÖ ¯ÖÏ ¿®Ö-¯Ö¡Ö ´Öë 26 ¯ÖÏ ¿®Ö Æï …• Ûéú¯ÖµÖÖ ¯ÖÏ ¿®Ö ÛúÖ ˆ¢Ö¸ ×»ÖÜÖ®ÖÖ ¿Öã ºþ Ûú¸ ®Öê ÃÖê ÖÆ»Öê , ¯ÖÏ ¿®Ö ÛúÖ ÛÎú´ÖÖÓ Ûú †¾Ö¿µÖ ×»ÖÜÖë …• ‡ÃÖ ¯ÖÏ ¿®Ö-¯Ö¡Ö Û Öê ¯ÖœÌ®Öê Ûê ×»Ö‹ 15 ×´Ö®Ö™ Û Ö ÃÖ´ÖµÖ ×¤üµÖÖ ÝÖµÖÖ Æî … ¯ÖÏ ¿®Ö-¯Ö¡Ö Û Ö ×¾ÖŸÖ¸üÞÖ ¯Öæ ¾ÖÖÔ ÆË®Ö ´Öë 10.15 ²Ö•Öê

×Û µÖÖ •ÖÖµÖê ÝÖÖ … 10.15

²Ö•Öê ÃÖê 10.30

²Ö•Öê ŸÖÛ ”ûÖ¡Ö Ûê ¾Ö»Ö ¯ÖÏ ¿®Ö-¯Ö¡Ö Û Öê ¯ÖœÌ ëÝÖê †Öî ¸ü ‡ÃÖ †¾Ö×¬Ö Ûê ¤üÖî ¸üÖ®Ö ¾Öê ˆ¢Ö¸ü-¯Öã ×ÃŸÖÛ Ö ¯Ö¸ü Û Öê ‡Ô ˆ¢Ö¸ü ®ÖÆüà ×»ÖÜÖë ÝÖê …• Please check that this question paper contains 12 printed pages.

• Code number given on the right hand side of the question paper should be written on thetitle page of the answer-book by the candidate.

• Please check that this question paper contains 26 questions.

• Please write down the Serial Number of the question before attempting it.

• 15 minutes time has been allotted to read this question paper. The question paper will be

distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the

question paper only and will not write any answer on the answer-book during this period.

úÖ› ®ÖÓ.Code No.

¯Ö¸ü õÖÖ£Öá Û Öê › Û Öê ˆ¢Ö¸ü-¯Öã ×ÃŸÖÛ Ö Ûê ´Öã ÜÖ-¯Öé Âš

¯Ö¸ü †¾Ö¿µÖ ×»ÖÜÖë …Candidates must write the Code on

the title page of the answer-book.

SET – 1



55/1/1 2

(v) •ÖÆ ÖÑ †Ö¾Ö¿µÖÛú Æ Öê †Ö¯Ö ×®Ö´®Ö×»Ö×ÜÖŸÖ ³ÖÖî ×ŸÖÛ ×®ÖµÖŸÖÖÓ ÛúÖë Ûê ú ´ÖÖ®ÖÖë ÛúÖ ˆ¯ÖµÖÖê ÝÖ Ûú¸ ÃÖÛúŸÖê Æï :

c = 3 × 108 m/s

h = 6.63 × 10–34 Js

e = 1.6 × 10–19 C

µ0 = 4π × 10–7 T m A–1

ε0 = 8.854 × 10–12 C2 N–1 m–2

1

4πε0

= 9 × 109 N m2 C–2

me = 9.1 × 10–31 kg

®µÖæ ™ÒÖò ®Ö Û Ö ¦ü¾µÖ´ÖÖ®Ö = 1.675 × 10–27 kg

¯ÖÏ Öê ™Öò ®Ö Û Ö ¦ü¾µÖ´ÖÖ®Ö = 1.673 × 10–27 kg

†Ö¾ÖÖê ÝÖÖ¦üÖê ÃÖÓ ÜµÖÖ = 6.023 × 1023 ¯ÖÏ ×ŸÖ ÝÖÏ Ö´Ö ´ÖÖê »Ö ²ÖÖê »™Ë•ÖÌ ´ÖÖ®Ö ×®ÖµÖŸÖÖÓ Û = 1.38 × 10–23 JK–1

General Instructions :

(i) All questions are compulsory. There are 26 questions in all.

(ii) This question paper has five sections : Section A , Section B , Section C , Section D

and Section E.

(iii) Section A contains five questions of one mark each, Section B contains five

questions of two marks each, Section C contains twelve questions of three marks

each, Section D contains one value based question of four marks and Section E

contains three questions of five marks each.

(iv) There is no overall choice. However, an internal choice has been provided in one

question of two marks, one question of three marks and all the three questions of

five marks weightage. You have to attempt only one of the choices in such

questions.

(v) You may use the following values of physical constants wherever necessary :

c = 3 × 108 m/s

h = 6.63 × 10–34 Js

e = 1.6 × 10–19 C

µ0 = 4π × 10–7 T m A–1

ε0 = 8.854 × 10–12 C2 N–1 m–2

1

4πε0

= 9 × 109 N m2 C–2

me = 9.1 × 10–31 kg

Mass of neutron = 1.675 × 10–27 kg

Mass of proton = 1.673 × 10–27 kg

Avogadro’s number = 6.023 × 1023 per gram mole

Boltzmann constant = 1.38 × 10–23 JK–1



55/1/1 3 [P.T.O.

ÜÖÞ› – †

Section – A

1. ¦ü¾µÖ´ÖÖ®Ö ‘m’ †Öî ¸ü †Ö¾Öê ¿Ö ‘q’ Û Ö Û Öê ‡Ô Û ÞÖ ‘v’ ¾Öê ÝÖ ÃÖê ×Û ÃÖß ‹Û ÃÖ´ÖÖ®Ö “Öã ´²ÖÛ ßµÖ õÖê ¡Ö, •ÖÖê Û ÞÖ Û ß ÝÖ×ŸÖ Û ß

×¤ü¿ÖÖ Ûê »Ö´²Ö¾ÖŸÖ Æî, ´Öë ¯ÖÏ ¾Öê ¿Ö Û üŸÖÖ Æî, ˆÃÖÛ ß ÝÖ×ŸÖ•Ö ‰ •ÖÖÔ ×Û ÃÖ ÖÏ Û Ö¸ü ¯ÖÏ³ÖÖ×¾ÖŸÖ ÆüÖê ŸÖß Æî ? 1

A particle of mass ‘m’ and charge ‘q’ moving with velocity ‘v’ enters the region of

uniform magnetic field at right angle to the direction of its motion. How does its

kinetic energy get affected ?

2. ×“Ö¡Ö ´Öë ×Û ÃÖß ¬ÖÖ¸üÖ¾ÖÖÆüß ¯Ö×¸ü®ÖÖ×»ÖÛ Ö Û Öê ×Û ÃÖß “ÖÖ»ÖÛ »Öæ ¯Ö (¯ÖÖ¿Ö) Û ß †Öê ¸ü ÝÖ×ŸÖ´ÖÖ®Ö ¤ü¿ÖÖÔ µÖÖ ÝÖµÖÖ Æî … »Öæ ¯Ö ´Öë

¯ÖÏ ê ×¸üŸÖ ¬ÖÖ¸üÖ Û ß ×¤ü¿ÖÖ ²ÖŸÖÖ‡‹ … 1

Figure shows a current carrying solenoid moving towards a conducting loop. Find the

direction of the current induced in the loop.

3. •Ö²Ö ×Û ÃÖß ×²Ö´²Ö Û Öê ×Û ÃÖß †¾ÖŸÖ»Ö ¤ü¯ÖÔ ÞÖ Ûê f †Öî ¸ü 2f Ûê ²Öß“Ö ¸üÜÖÖ •ÖÖŸÖÖ Æî, ŸÖ²Ö ²Ö®Ö®Öê ¾ÖÖ»ÖÖ ¯ÖÏ ×ŸÖ×²Ö´²Ö Ûî ÃÖÖ

ÆüÖê ŸÖÖ Æî – (i) ¾ÖÖÃŸÖ×¾ÖÛ †£Ö¾ÖÖ †Ö³ÖÖÃÖß †Öî ¸ü (ii) ”ûÖê ™Ö †£Ö¾ÖÖ ×¾Ö¾ÖÙ¬ÖŸÖ ? 1

When an object is placed between f and 2f of a concave mirror, would the image

formed be (i) real or virtual and (ii) diminished or magnified ?

4. ‡»Öê Œ™ÒÖò ®Ö Û ß ÝÖ×ŸÖ•Ö ‰ •ÖÖÔ Ûê ± »Ö®Ö Ûê ºþ¯Ö ´Öë ‡ÃÖÛ ß ¤ê-²ÖÎ ÖÝ»Öß ŸÖ¸ÓÝÖ¤î¬µÖÔ Ûê ×¾Ö“Ö¸üÞÖ Û Öê ÝÖÏ Ö± ÜÖà“ÖÛ ü

¤ü¿ÖÖÔ ‡‹ … 1

Draw a plot showing the variation of de Broglie wavelength of electron as a function

of its K. E.

5. ´ÖÖê ²ÖÖ‡»Ö ± Öê ®Ö ´Öë †ÖÝÖ´Öß ×ÃÖÝ®Ö»ÖÖë †Öî ¸ü ×®ÖÝÖÔ ´Öß ×ÃÖÝ®Ö»ÖÖë Û ß †Ö¾Öé ×¢ÖµÖÖÑ ×³Ö®®Ö ŒµÖÖë ÆüÖê ŸÖß Æî ? 1

Why is the frequency of outgoing and incoming signals different in a mobile phone ?



55/1/1 4

ÜÖÞ› – ²Ö

Section – B

6. ×Û ÃÖß “ÖÖ»ÖÛ ´Öë †Ö¾Öê ¿Ö ¾ÖÖÆüÛ Öë Ûê †¯Ö¾ÖÖÆü ¾Öê ÝÖ Û ß †¾Ö¬ÖÖ¸üÞÖÖ Û Ö ˆ¯ÖµÖÖê ÝÖ Û üÛê ˆÃÖ “ÖÖ»ÖÛ Û ß ¯ÖÏ ×ŸÖ¸üÖê¬ÖÛ ŸÖÖ†Öî ¸ü ¬ÖÖ¸üÖ ‘Ö®ÖŸ¾Ö Ûê ²Öß“Ö ÃÖÓ ²ÖÓ¬Ö ¾µÖã Ÿ¯Ö®®Ö Û ß×•Ö‹ … 2

Using the concept of drift velocity of charge carriers in a conductor, deduce the

relationship between current density and resistivity of the conductor.

7. †¬ÖÐ ã ×¾ÖŸÖ ¯ÖÏ Û Ö¿Ö †Öî ¸ü ¸î ×ÜÖÛ ŸÖ: ¬ÖÐ ã ×¾ÖŸÖ ¯ÖÏ Û Ö¿Ö Ûê ²Öß“Ö ×¾Ö³Öê ¤ü®Ö Û ß×•Ö‹ … †Ö¸êÜÖ Û ß ÃÖÆüÖµÖŸÖÖ ÃÖê ¾ÖÞÖÔ ®Ö Û ß×•Ö‹ ×Û ×Û ÃÖ ¯ÖÏ Û Ö¸ü ¯ÖÏ Û ßÞÖÔ ®Ö «Ö¸üÖ †¬ÖÐ ã ×¾ÖŸÖ ¯ÖÏ Û Ö¿Ö ¸î×ÜÖÛ ŸÖ: ¬ÖÐ ã ×¾ÖŸÖ ÆüÖê •ÖÖŸÖÖ Æî … 2

Distinguish between unpolarised and a linearly polarised light. Describe, with the helpof a diagram, how unpolarised light gets linearly polarised by scattering.

8. ¿¾Öê ŸÖ ¯ÖÏ Û Ö¿Ö ×Û ÃÖß Û ÖÑ “Ö Ûê ×¯ÖÏ •ûÌ ´Ö ÃÖê ÝÖã •Ö¸ü®Öê ¯Ö¸ü ¯Ö×¸üõÖê ×¯ÖŸÖ ÆüÖê •ÖÖŸÖÖ Æî …

»Öë ÃÖ ´Öî Û ü ÃÖæ ¡Ö Û Ö ˆ¯ÖµÖÖê ÝÖ Û üÛê µÖÆü ¤ü¿ÖÖÔ ‡‹ ×Û ×Û ÃÖß ×¤ü‹ ÝÖ‹ »Öë ÃÖ Û ß ± Öê Û ÃÖ ¤æ üß ˆÃÖ ¯Ö¸ü †Ö¯Ö×ŸÖŸÖ

¯ÖÏ Û Ö¿Ö Ûê ¾ÖÞÖÔ (¸ÓÝÖ) ¯Ö¸ü ×®Ö³ÖÔ ¸ü Û üŸÖß Æî … 2

Why does white light disperse when passed through a glass prism ?

Using lens maker’s formula, show how the focal length of a given lens depends upon

the colour of light incident on it.

9. ×“Ö¡Ö ´Öë ¤ü¿ÖÖÔ ‹ ÝÖ‹ ×®Ö¸üÖê¬Öß ×¾Ö³Ö¾Ö †Öî ¸ü ± Öê ™Öò ®Ö Û ß †Ö¯ÖŸÖ®Ö †Ö¾Öé ×¢Ö Ûê ²Öß“Ö ÝÖÏ Ö± Û Ö ˆ¯ÖµÖÖê ÝÖ Û üÛê ¯»ÖÖÓ Û ×®ÖµÖŸÖÖÓ Û ¯Ö×¸üÛ ×»ÖŸÖ Û ß×•Ö‹ … 2

Using the graph shown in the figure for stopping potential V/s the incident frequency

of photons, calculate Planck’s constant.



55/1/1 5 [P.T.O.

10. ®Öß“Öê ¤üß ÝÖµÖß ®ÖÖ×³ÖÛ ßµÖ †×³Ö×ÛÎ µÖÖ Û Öê ¯Öæ ¸üÖ Û ß×•Ö‹ : 2

(a)10

5 B +1

0n → 4

2He + ……

(b)94

42Mo +2

1H → 95

43Te + ……

†£Ö¾ÖÖ

µÖ×¤ü ×Û ÃÖß ®ÖÖ×³ÖÛ ßµÖ †×³Ö×ÛÎ µÖÖ ´Öë ¯ÖÏ Öê ™Öò ®ÖÖë †Öî ¸ü ®µÖæ ™ÒÖò ®ÖÖë ¤üÖê ®ÖÖë Û ß ÃÖÓ ÜµÖÖ ÃÖÓ ¸ü×õÖŸÖ ¸üÆüŸÖß Æî, ŸÖ²Ö ×Û ÃÖ ¯ÖÏ Û Ö¸ü ¦ü¾µÖ´ÖÖ®Ö Û Ö ºþ¯ÖÖ®ŸÖ¸üÞÖ ‰ •ÖÖÔ ´Öë (†£Ö¾ÖÖ ‡ÃÖÛ Ö ¾µÖã ŸÛÎ Ö) ÆüÖê ŸÖÖ Æî ? ‹Û ˆ¤üÖÆü¸üÞÖ ÃÖ×ÆüŸÖ ¾µÖÖÜµÖÖ Û ß×•Ö‹ …

Complete the following nuclear reactions :

(a)10

5 B +1

0n → 4

2He + ……

(b)94

42Mo +2

1H → 95

43Te + ……

OR

If both the number of protons and neutrons in a nuclear reaction is conserved, in what

way is mass converted into energy (or vice verse) ? Explain giving one example.

ÜÖÞ› – ÃÖ

Section – C

11. ×«¬ÖÐ ã ¾Ö †Ö‘Öæ ÞÖÔ →p Ûê ×Û ÃÖß ¾Öî ªã ŸÖ ×«¬ÖÐ ã ¾Ö Û Öê ×Û ÃÖß ‹Û ÃÖ´ÖÖ®Ö ×¾Öªã ŸÖ õÖê ¡Ö

→E ´Öë ¸üÜÖÖ ÝÖµÖÖ Æî … ‡ÃÖ ×«¬ÖÐ ã ¾Ö « Ö¸üÖ

†®Öã³Ö¾Ö ×Û ‹ •ÖÖ®Öê ¾ÖÖ»Öê ²Ö»Ö †Ö‘Öæ ÞÖÔ →τ Ûê ×»Ö‹ ¾µÖÓ •ÖÛ ¯ÖÏ Ö¯ŸÖ Û ß×•Ö‹ … ‡ÃÖ ¾µÖÓ •ÖÛ ´Öë »Ö´²Ö¾ÖŸÖ ÃÖ×¤ü¿ÖÖë Ûê ¤üÖê

µÖã Ý´ÖÖë Û Öê ¯ÖÆü“ÖÖ×®Ö‹ … 3

An electric dipole of dipole moment→p is placed in a uniform electric field

→E. Obtain

the expression for the torque→τ experienced by the dipole. Identify two pairs of

perpendicular vectors in the expression.

12. (a) R1 †Öî ¸ü R2 (R2 > R1) ×¡Ö•µÖÖ†Öë Ûê ¤üÖê ÝÖÖê »ÖßµÖ “ÖÖ»ÖÛ Öë Û Öê †Ö¾Öê ×¿ÖŸÖ ×Û µÖÖ ÝÖµÖÖ Æî … µÖ×¤ü ‡®Æë ×Û ÃÖß “ÖÖ»ÖÛ ŸÖÖ¸ü ÃÖê ÃÖÓ µÖÖê ×•ÖŸÖ ×Û µÖÖ •ÖÖŸÖÖ Æî, ŸÖÖê ‡®ÖÛê ¯Öé ÂšßµÖ †Ö¾Öê ¿Ö ‘Ö®ÖŸ¾ÖÖë Û Ö †®Öã ¯ÖÖŸÖ –ÖÖŸÖ Û ß×•Ö‹ …

(b) ×Û ÃÖß †ÃÖ´ÖÖ®Ö †®Öã ¯ÖÏ Ã£Ö Û Ö™ Ûê ¬ÖÖ×Ÿ¾ÖÛ “ÖÖ»ÖÛ ÃÖê Û Öê ‡Ô Ã£ÖÖµÖß ¬ÖÖ üÖ ¯ÖÏ ¾ÖÖ×ÆüŸÖ ÆüÖê üÆüß Æî … ‡ÃÖ “ÖÖ»ÖÛ Ûê †®Öã ×¤ü¿Ö Û Öî ®Ö ÃÖß ¸üÖ×¿Ö ×®ÖµÖŸÖ Æî : ×¾Öªã ŸÖ ¬ÖÖ¸üÖ, ¬ÖÖ¸üÖ ‘Ö®ÖŸ¾Ö, ×¾Öªã ŸÖ õÖê ¡Ö, †¯Ö¾ÖÖÆü “ÖÖ»Ö ? 3

(a) Two spherical conductors of radii R1 and R2 (R2 > R1) are charged. If they are

connected by a conducting wire, find out the ratio of the surface charge densities

on them.

(b) A steady current flows in a metallic conductor of non-uniform cross-section.

Which of these quantities is constant along the conductor : current, current

density, electric field, drift speed ?



55/1/1 6

13. ×“Ö¡Ö ´Öë ¤ü¿ÖÖÔ ‹ ÝÖ‹ ¤üÖê ×¾Öªã ŸÖ ¯Ö×¸ü¯Ö£ÖÖë ´Öë †Ö¤ü¿ÖÔ ‹ê ´Öß™¸ü (A) †Öî ¸ü †Ö¤ü¿ÖÔ ¾ÖÖê »™´Öß™¸ü (V) Ûê ¯ÖÖšËµÖÖÓ Û ×®Ö¬ÖÖÔ ×¸üŸÖ Û ß×•Ö‹ …

V

A

6 V

9 V

1Ω

1 Ω

+_

V

A

6 V

9 V

1 Ω

1Ω

_+

(a) (b) †£Ö¾ÖÖ

×“Ö¡Ö ´Öë ¤ü¿ÖÖÔ ‹ ÝÖ‹ ×¾Öªã ŸÖ ¯Ö×¸ü¯Ö£Ö ´Öë ¯ÖÏ ŸµÖê Û ¯ÖÏ ×ŸÖ¸üÖê¬ÖÛ ÃÖê ¯ÖÏ ¾ÖÖ×ÆüŸÖ ¬ÖÖ¸üÖ –ÖÖŸÖ Û ß×•Ö‹ … 3

4V 8V 1.0 Ω

0.5 Ω

3.0 ΩA B

4.5 Ω

6.0 Ω

ii

In the two electric circuits shown in the figure, determine the readings of ideal

ammeter (A) and the ideal voltmeter (V).

V

A

6 V

9 V

1Ω

1 Ω

+_

V

A

6 V

9 V

1 Ω

1Ω

_+

(a) (b) OR

In the circuit shown in the figure, find the current through each resistor.

4V 8V 1.0 Ω

0.5 Ω

3.0 ΩA B

4.5 Ω

6.0 Ω

ii



55/1/1 7 [P.T.O.

14. ˆ¯ÖµÖã ŒŸÖ †Ö¸êÜÖ Û ß ÃÖÆüÖµÖŸÖÖ ÃÖê (i) “Öã ´²ÖÛ ßµÖ ×¤üÛË ÖÖŸÖ †Öî ¸ü (ii) ®Ö×ŸÖ Û Öê ÞÖ ¯Ö×¸ü³ÖÖ×ÂÖŸÖ Û ß×•Ö‹ … µÖ×¤ü ×Û ÃÖß “Öã ´²ÖÛ ßµÖ ÃÖã ‡Ô Û Öê (i) ¬ÖÐ ã ¾ÖÖë, (ii) ×¾ÖÂÖã ¾ÖŸÖË ¾Öé ¢Ö ¯Ö¸ü ¸üÜÖë, ŸÖÖê ¾ÖÆü ×Û ÃÖ ×¤ü¿ÖÖ ´Öë ÃÖÓ Ûê ŸÖ Û êÝÖß ? 3

Define the following using suitable diagrams : (i) magnetic declination and (ii) angle

of dip. In what direction will a compass needle point when kept at the (i) poles and (ii)

equator ?

15. ×Û ÃÖß ¯Ö×¸ü®ÖÖ×»ÖÛ Ö ×•ÖÃÖ´Öë Û Öê ‡Ô Ã£ÖÖµÖß ¬ÖÖ¸üÖ I ¯ÖÏ ¾ÖÖ×ÆüŸÖ ÆüÖê ¸üÆüß Æî, ´Öë ÃÖÓ ×“ÖŸÖ “Öã ´²ÖÛ ßµÖ ‰ •ÖÖÔ Ûê ×»Ö‹, ¯Ö× ü®ÖÖ×»ÖÛ Ö Ûê “Öã ´²ÖÛ ßµÖ õÖê ¡Ö B, õÖê ¡Ö± »Ö A ŸÖ£ÖÖ »Ö´²ÖÖ‡Ô l Ûê ¯Ö¤üÖë ´Öë ¾µÖÓ •ÖÛ ¾µÖã Ÿ¯Ö®®Ö Û ß×•Ö‹ …

¯ÖÏ ×ŸÖ ‹Û ÖÓ Û †ÖµÖŸÖ®Ö ‡ÃÖ “Öã ´²ÖÛ ßµÖ ‰ •ÖÖÔ Û ß ŸÖã »Ö®ÖÖ ×Û ÃÖß ÃÖ´ÖÖ®ŸÖ¸ü ¯Ö×¼Û Ö ÃÖÓ¬ÖÖ×¸ü¡Ö ´Öë ÃÖÓ ×“ÖŸÖ ×Ã£Ö¸ü ¾Öî ªã ŸÖ ‰ •ÖÖÔ ‘Ö®ÖŸ¾Ö ÃÖê ×Û ÃÖ ÖÏ Û Ö¸ü Û ß •ÖÖŸÖß Æî ? 3

Derive the expression for the magnetic energy stored in a solenoid in terms of

magnetic field B, area A and length l of the solenoid carrying a steady current I.

How does this magnetic energy per unit volume compare with the electrostatic energy

density stored in a parallel plate capacitor ?

16. ×Û ÃÖß ¯Ö×¸ü¯Ö£Ö ´Öë 80 mH Ûê ¯ÖÏ ê ¸üÛ †Öî ¸ü 250 µF Ûê ÃÖÓ ¬ÖÖ×¸ü¡Ö Û Öê 240 V, 100 rad/s †Ö¯Öæ ÙŸÖ ÃÖê ÃÖÓ µÖÖê ×•ÖŸÖ ×Û µÖÖ ÝÖµÖÖ Æî … ¯Ö×¸ü¯Ö£Ö Û Ö ¯ÖÏ ×ŸÖ¸üÖê¬Ö ˆ¯ÖêõÖÞÖßµÖ Æî …

(i) ¬ÖÖ¸üÖ Û Ö rms ´ÖÖ®Ö ¯ÖÏ Ö¯ŸÖ Û ß×•Ö‹ …

(ii) ¯Ö×¸ü¯Ö£Ö «Ö¸üÖ †¾Ö¿ÖÖê ×ÂÖŸÖ Ûã »Ö †Öî ÃÖŸÖ ¿Ö×ŒŸÖ ŒµÖÖ Æî ? 3

A circuit containing an 80 mH inductor and a 250 µF capacitor in series connected to a

240 V, 100 rad/s supply. The resistance of the circuit is negligible.

(i) Obtain rms value of current.(ii) What is the total average power consumed by the circuit ?

17. ®Öß“Öê ×¤ü‹ ÝÖ‹ ¯ÖÏ ¿®ÖÖë Ûê ˆ¢Ö¸ü ¤üß×•Ö‹ : 3

(i) ÃÖ´ÖŸÖÖ¯Ö ´ÖÞ›»Ö Ûê ¿ÖßÂÖÔ ¯Ö ü †Öê •ÖÌ Öê ®Ö Û ß ¯ÖŸÖ»Öß ¯Ö¸üŸÖ ´ÖÖ®Ö¾Ö Û ß ˆ¢Ö¸ü•Öß×¾ÖŸÖÖ Ûê ×»Ö‹ ×®ÖÞÖÖÔ µÖÛ ŒµÖÖë Æï ? ¾Öî ªã ŸÖ-“Öã ´²ÖÛ ßµÖ Ã¯Öê Œ™Ò Ö Ûê ˆÃÖ ³ÖÖÝÖ Û ß ¯ÖÆü“ÖÖ®Ö Û ß×•Ö‹ ×•ÖÃÖÃÖê µÖÆü ×¾Ö×Û ¸üÞÖ ÃÖÓ ²ÖÓ ×¬ÖŸÖ Æî … ‡®Ö ×¾Ö×Û üÞÖÖë Û Ö ‹Û ´ÖÆü¢¾Ö¯Öæ ÞÖÔ †®Öã ¯ÖÏ µÖÖê ÝÖ ×»Ö×ÜÖ‹ …

(ii) †¾Ö¸üŒŸÖ ŸÖ¸ÓÝÖÖë Û Öê ‰ Â´ÖßµÖ ŸÖ¸ÓÝÖë ŒµÖÖë ´ÖÖ®ÖÖ •ÖÖŸÖÖ Æî ? µÖê ×Û ÃÖ ÖÏ Û Ö¸ü ˆŸ¯Ö®®Ö ÆüÖê ŸÖß Æï ? ÝÖÏ ß®Ö ÆüÖˆÃÖ ¯ÖÏ³ÖÖ¾Ö «Ö¸üÖ ¯Öé£¾Öß Û Öê ˆÂÞÖ ²Ö®ÖÖ‹ ¸üÜÖ®Öê ´Öë µÖê †¯Ö®Öß ŒµÖÖ ³Öæ ×´ÖÛ Ö ×®Ö³ÖÖŸÖß Æï ?

Answer the following questions :

(i) Why is the thin ozone layer on top of the stratosphere crucial for human survival ?

Identify to which a part of electromagnetic spectrum does this radiation belong

and write one important application of the radiation.

(ii) Why are infrared waves referred to as heat waves ? How are they produced ?

What role do they play in maintaining the earth’s warmth through the

greenhouse effect ?



55/1/1 8

18. ´ÖÖ¬µÖ´ÖÖë Ûê ×Û ÃÖß µÖã ÝÖ»Ö Ûê ×»Ö‹ ¯Ö¤ü “ ÛÎ ÖÓ ×ŸÖÛ Û Öê ÞÖ ” Û ß Ö×¸ü³ÖÖÂÖÖ ×»Ö×ÜÖ‹ …

15.0 cm ×¡Ö•µÖÖ Ûê ×Û ÃÖß ×ÃÖ×»ÖÞ›¸ü Û ß ŸÖ»Öß Ûê Ûê ®¦ü ¯Ö¸ü Û Öê ‡Ô ‹Û ¾ÖÞÖá ×²Ö®¤ã ÄÖÖê ŸÖ ‘S’ ¸üÜÖÖ Æî … ‡ÃÖ ×ÃÖ×»ÖÞ›¸ü ´Öë 7.0 cm ‰Ñ “ÖÖ‡Ô ŸÖÛ •Ö»Ö (†¯Ö¾ÖŸÖÔ ®ÖÖÓ Û 4/3) ³Ö¸üÖ Æî … ¯ÖÏ Û Ö¿Ö ×Û üÞÖ †Ö¸êÜÖ ÜÖà×“Ö‹ †Öî ¸ü •Ö»Ö ¯Öé Âš Û Ö ¾ÖÆü õÖê ¡Ö± »Ö ¯Ö×¸üÛ ×»ÖŸÖ Û ß×•Ö‹ ×•ÖÃÖÃÖê ¯ÖÏ Û Ö¿Ö ¾ÖÖµÖã ´Öë ×®ÖÝÖÔ ŸÖ ÆüÖê ÝÖÖ … 3

Define the term ‘critical angle’ for a pair of media.

A point source of monochromatic light ‘S’ is kept at the centre of the bottom of acylinder of radius 15.0 cm. The cylinder contains water (refractive index 4/3) to a

height of 7.0 cm. Draw the ray diagram and calculate the area of water surface through

which the light emerges in air.

19. ®Öß“Öê ×¤ü‹ ÝÖ‹ ŸÖß®Ö »Öë ÃÖÖë L1, L2 †Öî ¸ü L3 ´Öë ÃÖê ×Û ®Ö ¤üÖê Û Öê †Ö¯Ö ÃÖ¾ÖÖì ¢Ö´Ö ÃÖÓ³Ö¾Ö (i) ¤æ ü¤ü¿ÖÔ Û , (ii) ÃÖæ õ´Ö¤ü¿Öá

²Ö®ÖÖ®Öê Ûê ×»Ö‹ †×³Ö¥¿µÖÛ †Öî ¸ü ®Öê ×¡ÖÛ Ö Ûê ×»Ö‹ “Öã ®Öë ÝÖê ?

†¯Ö®Öê ¢Ö¸ü Û ß ¯Öã ×Â™ Ûê ×»Ö‹ Û Ö¸üÞÖ ¤üß×•Ö‹ …

»Öë ÃÖ ¿Ö×ŒŸÖ (P) « Ö¸ Ûú (A)

L1 6D 1 cm

L2 3D 8 cm

L3 10D 1 cm 3

Which two of the following lenses L1, L2 and L3 will you select as objective and

eyepiece for constructing best possible (i) telescope (ii) microscope ? Give reason to

support your answer.

Lens Power (P) Aperture (A)

L1 6D 1 cm

L2 3D 8 cm

L3 10D 1 cm

20. ˆ¯ÖµÖã ŒŸÖ †Ö¸êÜÖ ÜÖà“ÖÛ ü ¾µÖÖÜµÖÖ Û ß×•Ö‹ ×Û ×«×—Ö¸üß ´Öë ¾µÖ×ŸÖÛ üÞÖ ¯Öî ™®ÖÔ ¾ÖÖÃŸÖ¾Ö ´Öë , ¯ÖÏ ŸµÖê Û ×—Ö¸üß Ûê ‹Û »Ö ×—Ö¸üß ×¾Ö¾ÖŸÖÔ ®ÖÖë Û Ö †¬µÖÖ¸üÖê ¯ÖÞÖ Æüß Æî … ‡ÃÖ ¾µÖ×ŸÖÛ üÞÖ ¯Öî ™®ÖÔ †Öî ¸ü ‹Û ¾ÖÞÖá ÄÖÖê ŸÖ ÃÖê ¯ÖÏ Û Ö×¿ÖŸÖ ‹Û »Ö ×—Ö¸üß ´Öë ×¤üÜÖÖ‡Ô ¤ê®Öê ¾ÖÖ»Öê ¯Öî ™®ÖÔ ´Öë ×¾Ö³Öê ¤ü®Ö Û ü®Öê ¾ÖÖ»Öß ¤üÖê ´Öæ »Ö ×¾Ö×¿ÖÂ™ŸÖÖ‹Ñ ×»Ö×ÜÖ‹ … 3

Explain by drawing a suitable diagram that the interference pattern in a double slit is

actually a superposition of single slit diffraction from each slit.

Write two basic features which distinguish the interference pattern from those seen ina coherently illuminated single slit.

21. ‰ •ÖÖÔ-²Öî Þ› †Ö¸êÜÖÖë Ûê †Ö¬ÖÖ¸ü ¯Ö¸ü n- ¯ÖÏ Û Ö¸ü †Öî ¸ü p- ¯ÖÏ Û Ö¸ü Ûê †¬ÖÔ “ÖÖ»ÖÛ Öë Ûê ²Öß“Ö ×¾Ö³Öê ¤ü®Ö Û ß×•Ö‹ … ¯Ö¸ü´Ö ¿Öæ ®µÖ ŸÖÖ¯Ö †Öî ¸ü Û õÖ ŸÖÖ¯Ö ¯Ö¸ü ‡®ÖÛ ß “ÖÖ»ÖÛ ŸÖÖ†Öë Û ß ŸÖã »Ö®ÖÖ Û ß×•Ö‹ … 3

Distinguish between n-type and p-type semi-conductors on the basis of energy band

diagrams. Compare their conductivities at absolute zero temperature and at room

temperature.



55/1/1 9 [P.T.O.

22. (a) ×Û ÃÖß ¾µÖÖ¯ÖÛ ÃÖÓ “ÖÖ¸ü ¾µÖ¾ÖÃ£ÖÖ Û Ö ²»ÖÖò Û -†Ö¸êÜÖ ×¤üµÖÖ ÝÖµÖÖ Æî … 3

ÃÖæ “Ö®ÖÖ ÄÖÖêŸÖ

ÃÖÓ ¤ê¿Ö

×ÃÖÝ®Ö»Ö X

¯ÖÏ ê ×ÂÖŸÖ

×ÃÖÝ®Ö»Ö Y †×³ÖÝÖÏ ÖÆß

ÃÖæ “Ö®ÖÖ ˆ¯ÖµÖÖê ÝÖÛ ¢ÖÖÔ

ÃÖÓ ¤ê¿Ö ×ÃÖÝ®Ö»Ö

²ÖÖò ŒÃÖ ‘X’ †Öî ¸ü ‘Y’ ¯ÖÆü“ÖÖ×®Ö‹ ŸÖ£ÖÖ ‡®ÖÛê Û ÖµÖÔ ×»Ö×ÜÖ‹ …

(b) “ ×²Ö®¤ã ÃÖê ×²Ö®¤ã ” †Öî ¸ü “ ¯ÖÏ ÃÖÖ¸üÞÖ ” ÃÖÓ “ÖÖ¸ü Ûê ‡®Ö ¤üÖê œÓÝÖÖë ´Öë ×¾Ö³Öê ¤ü®Ö Û ß×•Ö‹ …(a) Given a block diagram of a generalized communication system.

InformationSource

Message

SignalX

Transmitted

SignalY User

Message

Signal

Identify the boxes ‘X’ and ‘Y’ and write their functions.

(b) Distinguish between “Point to Point” and “Broadcast” modes of communication.

ÜÖÞ› – ¤

Section – D

23. †´Öß®Ö Û Öê ×¯Ö”û»Öê Ûã ”û ´ÖÆüß®ÖÖë ÃÖê ×¾Ö¿ÖÖ»Ö ¸Ö×¿Ö Ûê ×¾Öªã ŸÖ Ûê ×²Ö»Ö ×´Ö»Ö ¸üÆê £Öê … ‡ÃÖÛê ²ÖÖ¸ê ´Öë ¾ÖÆü Ûã ”û ²Öê “Öî ®Ö

£ÖÖ … ‹Û ×¤ü®Ö ˆÃÖÛ Ö ×´Ö¡Ö ¸üÖê ×ÆüŸÖ, •ÖÖê ¾µÖ¾ÖÃÖÖµÖ ÃÖê ×¾Öªã ŸÖ †×³ÖµÖÓ ŸÖÖ £ÖÖ, ˆÃÖÛê ‘Ö ü †ÖµÖÖ … •Ö²Ö †´Öß®Ö ®Öê

†¯Ö®Öß ×“Ö®ŸÖÖ Ûê ²ÖÖ¸ê ´Öë ¸üÖê ×ÆüŸÖ Û Öê ²ÖŸÖÖµÖÖ, ŸÖÖê ˆÃÖ®Öê µÖÆü ¯ÖÖµÖÖ ×Û †´Öß®Ö Ûê ‘Ö¸ü ´Öë †³Öß ³Öß ŸÖÖ¯Ö¤üß¯ŸÖ »Öî ´¯Ö †Öî ¸ü

¯Öã ¸üÖ®Öê ±î ¿Ö®Ö Û Ö ‹µÖ¸üÛ ®›ß¿Ö®Ö¸ü ˆ¯ÖµÖÖê ÝÖ ×Û µÖÖ •ÖÖ ¸üÆüÖ Æî … ÃÖÖ£Ö Æüß ‘Ö¸ü ´Öë ³Öæ -ÃÖ´¯ÖÛÔ ®Ö ³Öß ˆ×“ÖŸÖ ®ÖÆüà £ÖÖ …

ˆÃÖ®Öê †´Öß®Ö ÃÖê 1000 W – 220 V Ûê ÃÖÖ´ÖÖ®µÖ ²Ö»²Ö Ûê Ã£ÖÖ®Ö ¯Ö¸ü 28 W Ûê CFL ²Ö»²ÖÖë Û Ö ˆ¯ÖµÖÖê ÝÖ Û ü®Öê

†Öî ¸ü ‘Ö¸ü ´Öë ˆ×“ÖŸÖ ³Öæ -ÃÖ´¯ÖÛÔ ®Ö Û üÖ®Öê Û Ö ¯Ö¸üÖ´Ö¿ÖÔ ×¤üµÖÖ … ˆÃÖ®Öê †Öî ¸ü ³Öß †®µÖ ˆ¯ÖµÖÖê ÝÖß ÃÖã —ÖÖ¾Ö ×¤ü‹ †Öî ¸ü ‡®Ö

ÃÖÓ ¤ê¿ÖÖë Û Öê †®µÖ ×´Ö¡ÖÖë ŸÖÛ ±î »ÖÖ®Öê Û Ö †ÖÝÖÏ Æü ×Û µÖÖ …

(i) †Ö¯ÖÛê ×¾Ö“ÖÖ¸ü ÃÖê ¸üÖê ×ÆüŸÖ ´Öë Û Öî ®Ö ÃÖê ÝÖã ÞÖ/´Öæ »µÖ ×¾Öª´ÖÖ®Ö Æï ?

(ii) ¯ÖÖ¸ü´¯Ö×¸üÛ ŸÖÖ¯Ö¤üß¯ŸÖ »Öî ´¯ÖÖë Û ß ŸÖã »Ö®ÖÖ ´Öë CFL †Öî ¸ü LED ŒµÖÖë ²Öê ÆüŸÖ¸ü Æï ?

(iii) ³Öæ -ÃÖ´¯ÖÛÔ ®Ö ÃÖê ×¾Öªã ŸÖ-×²Ö»Ö ×Û ÃÖ ¯ÖÏ Û Ö¸ü ÃÖê ‘Ö™ •ÖÖŸÖÖ Æî ? 4

Ameen had been getting huge electricity bill for the past few months. He was upset

about this. One day his friend Rohit, an electrical engineer by profession, visited his

house. When he pointed out his anxiety about this to Rohit, his friend found that

Ameen was using traditional incandescent lamps and using old fashioned air

conditioner. In addition there was no proper earthing in the house. Rohit advised himto use CFL bulbs of 28 W instead of 1000 W – 220 V and also advised him to get

proper earthing in the house. He made some useful suggestion and asked him to spread

this message to his friends also.

(i) What qualities/values, in your opinion did Rohit possess ?

(ii) Why CFLs and LEDs are better than traditional incandescent lamps ?

(iii) In what way earthing reduces electricity bill ?



55/1/1 10

ÜÖÞ› – µÖ Section – E

24. (a) ²ÖÖµÖÖê ÃÖÖ¾Ö™Ô ×®ÖµÖ´Ö Û Ö ˆ¯ÖµÖÖê ÝÖ Û üÛê ×¡Ö•µÖÖ R †Öî ¸ü N ±ê üÖë Û ß ¬ÖÖ¸üÖ¾ÖÖÆüß ¾Öé ¢ÖÖÛ Ö¸ü Ûã Þ›»Öß Ûê Û Ö¸üÞÖ Ûã Þ›»Öß Ûê †õÖ ¯Ö ü Ûã Þ›»Öß Ûê Ûê ®¦ü ÃÖê ‘ x’ ¤æ üß ¯Ö¸ü ×Ã£ÖŸÖ ×Û ÃÖß ×²Ö®¤ã ¯Ö¸ü ˆŸ¯Ö®®Ö “Öã ´²ÖÛ ßµÖ õÖê ¡Ö Ûê ×»Ö‹ ¾µÖÓ •ÖÛ ¾µÖã Ÿ¯Ö®®Ö Û ß×•Ö‹ … ‡ÃÖ Ûã Þ›»Öß Ûê Û Ö¸üÞÖ ˆŸ¯Ö®®Ö “Öã ´²ÖÛ ßµÖ õÖê ¡Ö ¸êÜÖÖ†Öë Û Öê †Ö¸ê×ÜÖŸÖ

Û ß×•Ö‹ …(b) ×“Ö¡Ö ´Öë ¤ü¿ÖÖÔ ‹ †®Öã ÃÖÖ¸ü ‘R’ ×¡Ö•µÖÖ Ûê ×Û ÃÖß ‹Û ÃÖ´ÖÖ®Ö ¾Öé ¢ÖÖÛ Ö¸ü »Öæ ¯Ö (¯ÖÖ¿Ö) ´Öë Û Öê ‡Ô ¬ÖÖ¸üÖ ‘I’ ×²Ö®¤ã M

ÃÖê ¯ÖÏ ¾Öê ¿Ö Û üÛê N ÃÖê ²ÖÖÆü¸ü ×®ÖÛ »ÖŸÖß Æî … »Öæ ¯Ö Ûê Ûê ®¦ü Ö¸ü ®Öê ™ “Öã ´²ÖÛ ßµÖ õÖê ¡Ö ¯ÖÏ Ö¯ŸÖ Û ß×•Ö‹ … 5

I

N

MI

O90°

†£Ö¾ÖÖ

(a) µÖÆü ¤ü¿ÖÖÔ ‡‹ ×Û ²ÖÖµÖÖê ÃÖÖ¾Ö™Ô ×®ÖµÖ´Ö Û Öê ¾Öî Û ×»¯ÖÛ ºþ¯Ö ÃÖê ‹ê ×´¯ÖµÖ¸ü ¯Ö×¸ü¯Ö£ÖßµÖ ×®ÖµÖ´Ö Ûê ºþ¯Ö ´Öë ×Û ÃÖ ÖÏ Û Ö¸ü ¾µÖŒŸÖ ×Û µÖÖ •ÖÖ ÃÖÛ ŸÖÖ Æî … ‡ÃÖ ×®ÖµÖ´Ö Û Ö ˆ¯ÖµÖÖê ÝÖ Û üÛê »Ö´²ÖÖ‡Ô ‘l’ †®Öã ¯ÖÏ Ã£Ö-Û Ö™ õÖê ¡Ö± »Ö ‘A’

Û ÃÖÛ ü ¯ÖÖÃÖ-¯ÖÖÃÖ ×»Ö¯Ö™ê ‘N’ ±ê üÖë Û ß ¯Ö×¸ü®ÖÖ×»ÖÛ Ö, ×•ÖÃÖÃÖê Ã£ÖÖµÖß ¬ÖÖ¸üÖ ‘I’ ¯ÖÏ ¾ÖÖ×ÆüŸÖ ÆüÖê ¸üÆüß Æî, Ûê ³ÖßŸÖ¸ü ˆŸ¯Ö®®Ö “Öã ´²ÖÛ ßµÖ õÖê ¡Ö Ûê ×»Ö‹ ¾µÖÓ •ÖÛ ¯ÖÏ Ö¯ŸÖ Û ß×•Ö‹ …

×Û ÃÖß ¯Ö×¸ü×´ÖŸÖ ¯Ö×¸ü®ÖÖ×»ÖÛ Ö, ×•ÖÃÖÃÖê ¬ÖÖ¸üÖ ‘I’ ¯ÖÏ ¾ÖÖ×ÆüŸÖ ÆüÖê ¸üÆüß Æî, Û ß “Öã ´²ÖÛ ßµÖ õÖê ¡Ö ¸êÜÖÖ‹Ñ †Ö¸ê×ÜÖŸÖ Û ß×•Ö‹ …

(b) »Ö´²ÖÖ‡Ô 0.45 m †Öî ¸ü ¦ü¾µÖ´ÖÖ®Ö 60 g Û ß Û Öê ‡Ô ÃÖß¬Öß õÖî ×ŸÖ•Ö “ÖÖ»ÖÛ ”û›Ì ‡ÃÖÛê ¤üÖê ®ÖÖë ×ÃÖ¸üÖë ¯Ö¸ü »ÖÝÖê ¤üÖê ‰ ¬¾ÖÖÔ¬Ö¸ü ŸÖÖ¸üÖë «Ö¸üÖ ×®Ö»Ö×´²ÖŸÖ Æî … ŸÖÖ¸üÖë ÃÖê ÆüÖê Û ü ‡ÃÖ ”û›Ì ÃÖê 5.0 A Û ß Ã£ÖÖµÖß ¬ÖÖ¸üÖ ¯ÖÏ ¾ÖÖ×ÆüŸÖ ÆüÖê üÆüß Æî … ˆÃÖ “Öã ´²ÖÛ ßµÖ õÖê ¡Ö Û Ö ¯Ö×¸ü´ÖÖÞÖ †Öî ¸ü ×¤¿ÖÖ –ÖÖŸÖ Û ß×•Ö‹ ×•ÖÃÖê ˆŸ¯Ö®®Ö Û ¸ü®Öê ¯Ö¸ü ŸÖÖ¸üÖë ´Öë ŸÖ®ÖÖ¾Ö ¿Öæ ®µÖ ÆüÖê •ÖÖ‹ …

(a) Use Biot-Savart law to derive the expression for the magnetic field due to a

circular coil of radius R having N turns at a point on the axis at a distance ‘ x’from its centre.

Draw the magnetic field lines due to this coil.

(b) A current ‘I’ enters a uniform circular loop of radius ‘R’ at point M and flows

out at N as shown in the figure.

Obtain the net magnetic field at the centre of the loop.

I

N

MI

O90°

OR



55/1/1 11 [P.T.O.

(a) Show how Biot-Savart law can be alternatively expressed in the form of

Ampere’s circuital law. Use this law to obtain the expression for the magnetic

field inside a solenoid of length ‘l’, cross-sectional area ‘A’ having ‘N’ closely

wound turns and carrying a steady current ‘I’.

Draw the magnetic field lines of a finite solenoid carrying current I.

(b) A straight horizontal conducting rod of length 0.45 m and mass 60 g is

suspended by two vertical wires at its ends. A current of 5.0 A is set up in therod through the wires.

Find the magnitude and direction of the magnetic field which should be set up in

order that the tension in the wire is zero.

25. (a) ÃÖÖê ®Öê Û ß ¯ÖŸÖ»Öß ¯Ö®®Öß «Ö¸üÖ α Û ÞÖÖë Û Ö ¯ÖÏ Û ßÞÖÔ ®Ö ¤ü¿ÖÖÔ ®Öê ¾ÖÖ»Öê ÝÖÖ‡ÝÖ¸ü-´ÖÖÃÖÔ ›®Ö ¯ÖÏ Û ßÞÖÔ ®Ö ¯ÖÏ µÖÖê ÝÖ Û ß µÖÖê •Ö®ÖÖ²Ö¨ ¾µÖ¾ÖÃ£ÖÖ Û Ö †Ö¸êÜÖ ÜÖà×“Ö‹ … ‹ê ÃÖÖ ŒµÖÖë Æî ×Û †×¬ÖÛ ÖÓ ¿Ö α- Û ÞÖ ¯Ö®®Öß ÃÖê ÃÖß¬Öê ×®ÖÛ »Ö ÝÖ‹†Öî ¸ü ˆ®ÖÛ Ö £ÖÖê ›ÌÖ ³ÖÖÝÖ Æüß ²Ö›Ì ê Û Öê ÞÖÖë ¯Ö¸ ¯ÖÏ Û ßÙÞÖŸÖ Æã†Ö ? ×Û ÃÖß ®ÖÖ×³ÖÛ Ûê Ûæ »ÖÖò ´Ö-õÖê ¡Ö ´Öë α- Û ÞÖÖë Ûê ¯ÖÏ õÖê ¯Ö ¯Ö£Ö ÜÖà×“Ö‹ … ÃÖÓ ‘Ö¼ ¯ÖÏ Ö“Ö»Ö Û Ö ŒµÖÖ ´ÖÆü¢¾Ö Æî †Öî ¸ü ‡ÃÖÃÖê ®ÖÖ×³ÖÛ Ûê ÃÖÖ‡•ÖÌ Ûê ×¾ÖÂÖµÖ ´Öë ŒµÖÖ ÃÖæ “Ö®ÖÖ ¯ÖÏ Ö¯ŸÖ ÆüÖê ÃÖÛ ŸÖß Æî ?

(b) 7.7 MeV Ûê ×Û ÃÖß α- Û ÞÖ Û ß, ®ÖÖ×³ÖÛ (Z = 80) ÃÖê õÖÞÖ³Ö¸ü Ûê ×»Ö‹ ×¾Ö üÖ´ÖÖ¾ÖÃ£ÖÖ ´Öë †Ö®Öê ŸÖ£ÖÖ ×¤ü¿ÖÖ ¯ÖÏ ×ŸÖ»ÖÖê ´Ö®Ö ÃÖê ¯Öæ ¾ÖÔ ÃÖ´Öß¯ÖÃ£Ö ¤æ üß Û Ö †ÖÛ »Ö®Ö Û ß×•Ö‹ … 5

†£Ö¾ÖÖ(a) ¸ü¤ü¸ü± Öê ›Ô ´ÖÖò ›»Ö Û ß ¾ÖÆü ¤ üÖê ´ÖÆü¢¾Ö¯Öæ ÞÖÔ ÃÖß´ÖÖ‹Ñ ×»Ö×ÜÖ‹ •ÖÖê ¯Ö¸ü´ÖÖÞ¾ÖßµÖ Ã¯Öê Œ™Ò Ö Û ß ¯ÖÏ ê ×õÖŸÖ ×¾Ö×¿ÖÂ™ŸÖÖ†Öë

Û ß ¾µÖÖÜµÖÖ ®ÖÆüà Û ü ÃÖÛ à … ²ÖÖê ¸ü Ûê ÆüÖ‡›ÒÖê •Ö®Ö ¯Ö¸ü´ÖÖÞÖã Ûê ´ÖÖò ›»Ö «Ö¸üÖ ‡®ÖÛ ß ¾µÖÖÜµÖÖ ×Û ÃÖ ¯ÖÏ Û Ö¸ü Û ß ÝÖµÖß ?

×¸ü›²ÖÝÖÔ ÃÖæ ¡Ö Û Ö ˆ¯ÖµÖÖê ÝÖ Û üÛê Hα »ÖÖ‡®Ö Û ß ŸÖ¸ÓÝÖ¤î¬µÖÔ Û Ö Ö×¸üÛ »Ö®Ö Û ß×•Ö‹ …

(R = 1.1 × 107 m–1 »Öß×•Ö‹ )(b) ²ÖÖê ¸ü Ûê †×³ÖÝÖé ÆüßŸÖÖë Û Ö ˆ¯ÖµÖÖê ÝÖ Û üÛê ÆüÖ‡›ÒÖê •Ö®Ö ¯Ö¸ü´ÖÖÞÖã Û ß n ¾Öà Û õÖÖ Û ß ×¡Ö•µÖÖ Ûê ×»Ö‹ ¾µÖÓ •ÖÛ ¯ÖÏ Ö¯ŸÖ

Û ß×•Ö‹ …(a) Draw a schematic arrangement of Geiger-Marsden experiment showing the

scattering of α-particles by a thin foil of gold. Why is it that most of the

α-particles go right through the foil and only a small fraction gets scattered atlarge angles ?

Draw the trajectory of the α-particle in the coulomb field of a nucleus. What isthe significance of impact parameter and what information can be obtained

regarding the size of the nucleus ?

(b) Estimate the distance of closest approach to the nucleus (Z = 80) if a 7.7 MeV

α-particle before it comes momentarily to rest and reverses its direction.

OR(a) Write two important limitations of Rutherford model which could not explain

the observed features of atomic spectra. How were these explained in Bohr’s

model of hydrogen atom ?

Use the Rydberg formula to calculate the wavelength of the Hα line.

(Take R = 1.1 × 107 m–1).

(b) Using Bohr’s postulates, obtain the expression for the radius of the nth orbit in

hydrogen atom.



55/1/1 12

26. (a) ×“Ö¡Ö ´Öë ×Û ÃÖß µÖã ×ŒŸÖ ‘X’ «Ö¸üÖ ×®Ö¾Öê ¿Öß ŸÖ¸ÓÝÖºþ¯Ö Û Öê ×®ÖÝÖÔ ŸÖ ŸÖ¸ÓÝÖºþ¯Ö ´Öë ºþ¯ÖÖ®ŸÖ×¸üŸÖ ÆüÖê ŸÖÖ ¤ü¿ÖÖÔ µÖÖ ÝÖµÖÖ Æî … ‡ÃÖ µÖã ×ŒŸÖ Û Ö ®ÖÖ´Ö ×»Ö×ÜÖ‹ †Öî ¸ü ˆ¯ÖµÖã ŒŸÖ ¯Ö×¸ü¯Ö£Ö «Ö¸üÖ ‡ÃÖÛê Û ÖµÖÔ Û ß ¾µÖÖÜµÖÖ Û ß×•Ö‹ … ‡ÃÖÛ ß ¾ÖÖê »™ŸÖÖ »Ö×²¬Ö †Öî ¸ü ¿Ö×ŒŸÖ »Ö×²¬Ö Ûê ×»Ö‹ ¾µÖÓ •ÖÛ ¾µÖã Ÿ¯Ö®®Ö Û ß×•Ö‹ … 5

µÖã ×ŒŸÖ

X

(b) CE ×¾Ö®µÖÖÃÖ ´Öë †Ö¬ÖÖ¸ü ²ÖÖµÖ×ÃÖŸÖ ™ÒÖÓ ×•ÖÃ™¸ü Û Ö †Ó ŸÖ¸üÞÖ †×³Ö»ÖõÖÞÖ ÜÖà×“Ö‹ … Ã¯ÖÂ™ ºþ¯Ö ÃÖê ¾µÖÖÜµÖÖ

Û ß×•Ö‹ ×Û ‡ÃÖ ¾ÖÛÎ Û Ö Û Öî ®Ö ÃÖÖ õÖê ¡Ö ¯ÖÏ ¾Ö¬ÖÔ Û Ûê ºþ¯Ö ´Öë ˆ¯ÖµÖÖê ÝÖ ×Û µÖÖ •ÖÖŸÖÖ Æî …†£Ö¾ÖÖ

(a) ¯Ö×¸ü¯Ö£Ö †Ö¸êÜÖ Û ß ÃÖÆüÖµÖŸÖÖ ÃÖê ×Û ÃÖß ¯Öæ ÞÖÔ ŸÖ¸ÓÝÖ ×¤üÂ™Û Ö¸üß Ûê Û ÖµÖÔ Û ß ÃÖÓ õÖê ¯Ö ´Öë ¾µÖÖÜµÖÖ Û ß×•Ö‹ … ‡ÃÖÛê ×®Ö¾Öê ¿Öß †Öî ¸ü ×®ÖÝÖÔ ŸÖ ŸÖ¸ÓÝÖºþ¯Ö †Ö»Öê ×ÜÖŸÖ Û ß×•Ö‹ …

(b) ×“Ö¡Ö ´Öë ¤ü¿ÖÖÔ ‹ ÝÖ‹ ¯Ö×¸ü¯Ö£Ö Ûê ŸÖã »µÖ ŸÖÛÔ ÝÖê ™ ¯ÖÆü“ÖÖ×®Ö‹ … ×®Ö¾Öê ¿Ö A †Öî ¸ü B Ûê ÃÖ³Öß ÃÖÓ ³Ö¾Ö ´ÖÖ®ÖÖë Ûê ×»Ö‹ ÃÖŸµÖ´ÖÖ®Ö ÃÖÖ¸üÞÖß ÜÖà×“Ö‹ …

(a) Figure shows the input waveform which is converted by a device ‘X’ into an

output waveform. Name the device and explain its working using the proper

circuit. Derive the expression for its voltage gain and power gain.

DeviceX

(b) Draw the transfer characteristic of a base biased transistor in CE configuration.

Explain clearly which region of the curve is used in an amplifier.

OR

(a) Explain briefly, with the help of circuit diagram, the working of a full wave

rectifier. Draw its input and output waveforms.

(b) Identify the logic gate equivalent to the circuit shown in the figure.

Draw the truth table for all possible values of inputs A and B.

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55 1 1 Physics (Theory) SSO 1 C