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CBSE Class 12 Physics Question Paper 2023 (Set 1 - 55/1/1) Wedanti, LIVE ONLINE TUTORING Waa fae : PrHciHead rg Bl FEI AAI & UEC AN FAST AE 4 Wer BINT : (i) 3a PI-WAY 35 We & | At We Altare & | (ii) weyM-W Ua ald fnhae-%, G1, 7s / (ii) BWSR T7 TEN 1 418 TH FelIHeNA (MCQ) VSR H UH-Uh HAG H WHT S | (iv) QUS aA WI Fe 19 4 25 TH Hld AY-IHI (VSA) VON H G-A Ab] H IPA é / (vy) GUST 97 GOT 26 4 30 TH AY-sHA (SA) VOR Aaa aH H T9T S| (vi) Wusay 797 Gen 31433 ae Ae.sala (LA) VaR UWa-Ura Hal & eI & | (vii) QUES A 797 GEN 34 F385 FA-WMINI AN-AN AG) & IPT FB | (viii) 984-94 4 Way feed Zé fen ras / Fah, GEG H2 IAF, Ger d2 War T GST H3 WAH I GE FH2 WY AIRh laned Bl Wad (ea TAT e | (ix) pep Hi sva7 ahta & | Mire MAMhl & AMIRI WA, HATHA AGAR FTNT Fr : c=3x10° m/s h = 6-63 x 10-4 Js e=16x10%C Up = 40 x 10? ae A Ey = 8-854 x 10° C*N 1m” | Ante ne -~9x109Nm’?C? sclteld Hl GUAM (m,) = 9-1 x 1073! kg Yet Hl GAIAM = 1-675 x 10-7! kg Wlelt Hl OMA = 1-673 x 10-7! ke STENT GEA = 6-023 x 1077 oie UTA Ala (per gram mole) aeesa adh = 1-38 x 10-28 JK} 55/1/11 Page 2 of 27 Wedanti, LIVE ONLINE TUTORING ae f=) / SECTION A 1. A point charge situated at a distance ‘r’ from a short electric dipole on its axis, experiences a force F . If the distance of the charge is ‘2r’, the force on the charge will be: F F F F &. BS & as d) — (a) 16 (b) 3 (c) 4 (d) 5 Zs For a metallic conductor, the correct representation of variation of resistance R with “ree Tis: Ra R R oO o o ® oO oO o O a S = q oe cS co o | / TR a th Hh R Ri R ov 0 vo dv Ra pe aan oc Temp. oN Temp. (a) (c) 3. The potential difference across a cell in an open circuit is 8 V. It falls to 4 V when a current of 4 A is drawn from it. The internal resistance of the cell is: (a) 490 (b) 380 (c) 20 (d) 10 4, A steady current flows through a metallic wire whose area of cross-section (A) increases continuously from one end of the wire to the other. The magnitude of drift velocity (v,) of the free electrons as a function of ‘A’ can be shown by : Vd | 7 Vd | 4 A A A A D. A diamagnetic substance is brought near the north or south pole of a bar magnet. It will be : (a) repelled by both the poles. (b) attracted by both the poles. (c) repelled by the north pole and attracted by the south pole. (d) attracted by the north pole and repelled by the south pole. 55/1/1 Page 5 of 27 P.T.O. Wedanti, LIVE ONLINE TUTORING aus os 6. le FAH HPrseit rast ASA 8-0 cm es AM Mad 40 Hi gz, Aad Seale aN & afta: 2 Yeas ofa Gas At aiefis ara @ 3-0 x 10-2 T afer & fare waa afar geahra aa A ye amt tél @ | sa Huedil A oita sft fa.a1. Ta (emf) 2 : (a) O12V (b) O15 V (c) 0:19 V (d) O22 V 7 arta a thet sade aes PSRQ al ewial va @ fad ada AT PQ a wfeta @ 2 aM PSRQ aw vies stevfig 2 | Ta PQ AN V A ala Hoes oe @ a site faa. aa (emf) & Ua Aeafiftaa FS fa oe fh ze7 ara 2 ? “x x =x x Se OT ZX S I Pp —————Se «Pr x x x x xX IX X M xIx IIx x x x x IIx x l v+— xIx IIx x x x x IIx x “fs xX x xX x xX Tx x N x sgh og x x xX xX US x <———__ x ——__—> ~ => (a) yeah aa (B) (b) an(v) (c) whaler (r) (d) PQA aeaTs 8. fedl ae at arate ae at ofa 4, aah at ofeaiatt & die sca fagld ani eldl @ doy, 1 do, Eh b) ——* (a) Ug ar (b) iy dt do, 1 do, (c) “Oa (d) é, dt Fel Udit & AAT set = | 9. wed al f & feet sada ci & fay fare sik sah arediah oiateta ata Al ads att ste 2 : (a) 3A (b) f (c) 2f (d) 4f 55/1/11 Page 6 of 27 Wedanti, LIVE ONLINE TUTORING ae ia 6. A circular coil of radius 8-0 cm and 40 turns is rotated about its vertical 2 diameter with an angular speed of 28 rad s-! in a uniform horizontal TU magnetic field of magnitude 3-0 x 107? T. The maximum emf induced in the coil is : (a) O12V (b) O15 V (c) 0:19 V (d) 0O22V a Figure shows a rectangular conductor PSRQ in which movable arm PQ has a resistance ‘r’ and resistance of PSRQ is negligible. The magnitude of emf induced when PQ is moved with a velocity ¥ does not depend on : x <x x LK xX B@ ie = | > . (a) magnetic field (B ) (b) velocity ( v ) (c) resistance (r) (d) length of PQ 8. In the process of charging of a capacitor, the current produced between the plates of the capacitor is : d 1d (a) Wy 2 ob) 1% dt Lo dt d d ) eg (qy) 1s dt €, dt where symbols have their usual meanings. 9. For a concave mirror of focal length ‘f’, the minimum distance between the object and its real image is: (a) zero (b) f (c) 2f (d) 4f 55/1/11 Page 7 of 27 P.T.O. i 14. ora Perch Ara aneharrers ht fret Preketsht arte Ft area men 3 mnie Ren wen a, a: (a) Zeal Viet ae ae | (b) Fé p-THR Hl Aah GA Va z | (c) Ba Adare Haw sclera frat (era) F sie std & | (d) Alem (STaTaah) WAT] cial WA SA STS | 15. n-THe & Sit Soll-dug ag 4, de avs FI acl Eo AK aa Sal EK E, h Stal Aaa Hl Hie Std z : (a) 10eV (b) leV (c) O-1eV (d) O-OleV WT FET 16 G18 sfyayq (A) A SRT (R) VON DH IIS | a HIT few WT a — (TTA Uh Al AMAT (A) TH GA Bl ART (R) ERI sited teal TAT & | Hel FR Aret fu 12 HIST (a), (b), (c) HR (d) FB Fr Ahr | (a) after (A) SR SR (R) CH Gal @ SR HR (R), BHA (A) HI Gel CARA A z | (b) after (A) SK SRT (R) GAT Gal S, WY PROT (R), siftHaa (A) FT Gal caren Fe? Ha ze | (c) site (A) Fel 8, Wed HRT (R) Wet = | (da) aftr (A) Ted & AAT HRT (R) Ht ed & | 16. ayer (A): Ta fret arr Hl ws al feet sad arate aa 4 var sire 8, dl aa ta 3a os & Mat arfed al aid & PRT (R): PR UH sarah yas z | 55/1/11 Page 10 of 27 Wedanti, LIVE ONLINE TUTORING i O : 14. When an intrinsic semiconductor is doped with a small amount of trivalent impurity, then : (a) its resistance increases. (b) it becomes a p-type semiconductor. (c) there will be more free electrons than holes in the semiconductor. (d) dopant atoms become donor atoms. 15. In the energy-band diagram of n-type Si, the gap between the bottom of the conduction band Ec and the donor energy level Ep is of the order of : (a) 10eV (b) leV (c) O-leV (d) 0-01leV Questions number 16 to 18 are Assertion (A) and Reason (R) type questions. Two statements are given — one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the codes (a), (b), (c) and (d) as given below. (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). (b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A). (c) Assertion (A) is true, but Reason (R) is false. (d) Assertion (A) is false and Reason (R) is also false. 16. Assertion (A): When a bar of copper is placed in an external magnetic field, the field lines get concentrated inside the bar. Reason (R): Copper is a paramagnetic substance. 55/1/1 Page 11 of 27 P.T.O. 17. 18. 19. 20. 21. 55/1/1 i srfirasers (A); eee ceo % Reel at reali & sta were yea Bar 2 PR (R): feet cm & at fag ald 4 aaM all W ald & A sa THR TAM hel Hie Ald & | aepy7 (A): Tertaga srs wert Al Horch vepla al Pala Hea z | PRT (R): eect argh & alse argtvat & fee yeri-lfaga a stad faferront hl dtaat & Baar act S| Ws ad fect tom wo asl aT V = (3-0 x 105 m/s) i 8 3a BaF yalta fen wae fret as gerta aa B= (0-4) 1+(037T) j] Baa? | ga aa 8 oo cpr caer uftafad A 1 i, | ak k WAM x,y sik Zz AA ch BAM Ul aes & Tat Ver Ho few say SN GIA BATA 4:8 x 107 Chkg 2 | feat ufadt faga aa aro tha qeachia aa sit oftad? gertta da & PR Uta faa aa wx ferme Ath | sad a fener Ve oT sift streardt a ferar SH Wha & ? AI Se AL Yfke Aihaw | (m) Beta fag wr svar ath fdt aad a ol feet et aeaat at Ud he Aet AAde YS W stadt eal aren fw sta witaa | aad & at & faa ar Gear ofl Ata | AMAT (a) wradl este At qe 4 wad qxaxte cpl Mertena vat ct ard & ? al PRA ed SC AU SA AL OMe ATKAT | Page 12 of 27 22. 23. 24. 25. 26. 55/1/1 Wedanti, LIVE ONLINE TUTORING a f=) / Two coherent monochromatic light beams of intensities I and 4I superpose each other. Find the ratio of maximum and minimum intensities in the resulting beam. 2 The ground state energy of hydrogen atom is — 13-6 eV. What is the potential energy and kinetic energy of an electron in the third excited state ? 2 (a) Differentiate between intrinsic and extrinsic semiconductors. 2 OR (b) Draw the circuit arrangement for studying the V — I characteristics of a p-n junction diode in forward bias and reverse bias. Show the plot of V — I characteristic of a silicon diode. 2 Briefly explain how the diffusion and drift currents contribute to the formation of potential barrier in a p-n junction diode. Z SECTION C (a) Twelve negative charges of same magnitude are equally spaced and fixed on the circumference of a circle of radius R as shown in Fig. (1). Relative to potential being zero at infinity, find the electric potential and electric field at the centre C of the circle. (b) If the charges are unequally spaced and fixed on an arc of 120° of radius R as shown in Fig. (11), find electric potential at the centre C. 3 (1) (11) Page 15 of 27 P.T.O. i 27. () whetta fhe vor sider a fia @ 2 soa thot site Fl Gerad a frat soft LCR ahaa, at fret ald v =v,, sin ot 4 Fathi 2, Ht ohtareant & ferme cares oct Fifa | STOTT (@) alt v=v, sin ot, MAF o Hf alia frat aT Gea @, A Gaited tere soft LCR akay & saare & few wd ad Ale | Sa SRS HI seria Ait frat wt fet sof LCR kaa At stare sitafa Tye aedt S| feat ao LCR uke 4 sraht & ae faa at ch fear Ht alt & fae om iran | 28. fasat r Hi feet cet ufsrierenr 4 ofa were ees A et At Ge ne | a uate 4 vated Ut I = Ip sin wot S| Sah eg H Mee sah UNI AK N il Al alg Hrscht Ha ape fers 2 | (>) spree 4 oita faa. aa (emf) eI 2 ? (@) prec sik uferice & da aa WeHca Pe ? 29. -HIStclst HI Vera-laegd wtp feel aig b Ws F sclaeia Seas Al TET fra Te Ata & 28a F cane Aika | (m) srafad fat bt fata dlacisit & fou veprsi-fagd at ml AE tae fava & ary faa umm Piaent cuigu, aan (@) sated fatcnt Ft dian & ara venrs-faga at om far al aad & fau mm Pita | 30. (%) @Sshn wary & fou sat EK ate Gifae | cost aa, gea aa sik sah Ba Al Aral H AaGSa AHA Hl sifeha AtHarT | AMAT (@) fata attet & ftw saa Gea b AY Sq Sol Mid Beas & faa a em & feu arte difae sik sai al fasivarsil a seca Aisa | seh atreat A ora: assla aes AT Slee ? 55/1/11 Page 16 of 27 27. 28. 29. 30. 55/1/1 Wedanti, LIVE ONLINE TUTORING i De (a) How does the resistance differ from impedance ? With the help of a suitable phasor diagram, obtain an expression for impedance of a series LCR circuit, connected to a source v = v,, sin at. 3 OR (b) Find the condition for resonance in a series LCR circuit connected to a source V = V;, sin wt, where @ can be varied. Give the factors on which the resonant frequency of a series LCR circuit depends. Plot a graph showing the variation of electric current with frequency in a series LCR circuit. 3 A long solenoid of radius r consists of n turns per unit length. A current I = Ip sin ot flows in the solenoid. A coil of N turns is wound tightly around it near its centre. What is : (a) the induced emf in the coil ? (b) the mutual inductance between the solenoid and the coil ? 3 How does Einstein’s photoelectric equation explain the emission of electrons from a metal surface ? Explain briefly. Plot the variation of photocurrent with : (a) collector plate potential for different intensity of incident radiation, and (b) intensity of incident radiation. 3 (a) Draw the energy level diagram for hydrogen atom. Mark the transitions corresponding to the series lying in the ultraviolet region, visible region and infrared region. 3 OR (b) Draw a diagram to show the variation of binding energy per nucleon with mass number for different nuclei and mention its two features. Why do lighter nuclei usually undergo nuclear fusion ? 3 Page 17 of 27 P.T.O. Wedanti, Wedanti, LIVE ONLINE TUTORING i 32. (%) (i) feet aad seaqa & oro qachiy aa & fou aa-arad faa foRaw | sa faa apr soarT teh fsa ‘a’ & feel Gare TIT, faae ant TP varied at tél 2, Hee RH Baha aa & few are aah ured Aifsre | feel ar uret & fee qeacha eta Al fee at Shia hid St Grachla aa Lat Gitar | (i) bls sclaeta fret alte Al qaran Hat 4 107 ms-l Fl aa a Usa at tal @ | afe Har At fea 10-19 m 2, at Ham 4a CRA Ht Gel Scleeld SRI Soa INT aa AAT | 5 AAAy (@) Gi) Feat aa 4 fra fest oad He ses KR SR Ga fae oie oacas aAtfre | sa fam or secte aif aI sa aa At fern at Pathe pet ch fer suai fra area @ | ae wd dif fae steia ae get (1) atftenaa, atk (2) Fras Bia 2 | Gi) at aed le GAR AR ASK BAA A Hat a 25 om al K 21 gq ad a facta femot d mam: 5-0 A AK 25 A oe varfed a tat S | AR BST 10 cm MTS MW AR ASM snifea aa ol UT Ufteptetd ART 5 33. (6) @ (1) Satire ted anh faada ted & oe al sie ferfan | (2) ane fefedt sam a feet at areal & am fatter ha & feat ders ft ard 2 | 55/1/11 Page 20 of 27 Wedanti, LIVE ONLINE TUTORING i ints 32. (a) (i) State Biot-Savart’s law for the magnetic field due to a current carrying element. Use this law to obtain an expression for the magnetic field at the centre of a circular loop of radius ‘a’ and carrying a current ‘’?. Draw the magnetic field lines for a current loop indicating the direction of magnetic field. (ii) An electron is revolving around the nucleus in a circular orbit with a speed of 10’ ms-!. If the radius of the orbit is 1071° m, find the current constituted by the revolving electron in the orbit. 5 OR (b) () Derive an expression for the force acting on a current carrying straight conductor kept in a magnetic field. State the rule which is used to find the direction of this force. Give the condition under which this force is (1) maximum, and (2) minimum. (i) Two long parallel straight wires A and B are 2-5 cm apart in air. They carry 5-0 A and 2-5 A currents respectively in opposite directions. Calculate the magnitude of the force exerted by wire A on a 10 cm length of wire B. 5 33. (a) (i) (1) Write two points of difference between an interference pattern and a diffraction pattern. (2) Name any two factors on which the fringe width in a Young’s double-slit experiment depends. 55/1/1 Page 21 of 27 P.T.O. 55/1/1 (ii) (1) (ii) a os an & fet tefett vart 4 dt fattat & dhe goa faker 4 Tae arel Verret At Tees TAT 100 TAT | (1) orgie sheate sik Pacadi shee & ota aie yard aT tsa A Ufc ArharT | (2) fatat 4 50 cm at We fea We WO CMT Shesal H A att oftenietd AIste | ATAT dpa Fst RH Hy Mes WS n, A no ATadaHl H meant Hl Uh-cat FIA HU se | n, AWtadaH H Ae A alg facia fara ga oss S al u WCET @ SIN WSS BM SUH Thirst n, Wad HAMA A TS Uva Nas lu 3K vo aa Hay oacga FAINT | at H AIC SqaK 6-0 cm fs & feel sa ara & Tet 4 Tet & GC A 3-0 cm A W HES Bel AY Hl Farge SHI BIN @ | Mel & Vala Hl HV 1-528 | ay A feel oat fag EA Tet Al ade 4 4 Cad W sa Gage Al are feyta aa AIT | Page 22 of 27 Wedanti, LIVE ONLINE TUTORING SECTION E 34. The following figure shows a circuit diagram. We can find the currents through and potential differences across different resistors using Kirchhoff’s rules. h g f Answer the following questions based on the above : (a) Which points are at the same potential in the circuit ? 1 (b) What is the current through arm bg ? 1 (c) Find the potential difference across resistance Rg. 2 OR (c) What is the power dissipated in resistance Rog ? Z 55/1/11 Page 25 of 27 P.T.O. LIVE ONLINE TUTORING i 35. teifran esede Um Geld Haass 2 Sl Usditar FH Wa GM ote spite Gra @ | sar sam et b ffcu & wa A fe aa @ wife saat Arad Sit soils HM HAM: 2-41 BIN 24-5° S at fH ER H sryadarH 3ik Hiidh HUT h AMAT Meat & | SAH St Hh Ul WT Bld & | Aal ah fh als vein sitet ft Re sik cetera asedte & sre faves set He ral & | Selferaa csede F a4 feet aHare Fysret st ABC & Uh Sah K le THT fe] STATA STI Ax Tel B A L B C Sth SUR WW AeafaiRad Weal & Sat IN - (H) Sa VHT for ar se ss F ys BU oe aithad INT | 1 (a) fsa yd yer a an aa Ate | 1 (7) got sreaite aad & at srpyarnt Al Gata A career Alfa | 2 STAT (1) ver & oof ordi arada At often fafau | sah SA & few a ad Faisy | Z 55/1/11 Page 26 of 27 30. 55/1/1 Wedanti, LIVE ONLINE TUTORING i Strontium titanate is a rare oxide — a natural mineral found in Siberia. It is used as a substitute for diamond because its refractive index and critical angle are 2-41 and 24-5°, respectively, which are approximately equal to the refractive index and critical angle of diamond. It has all the properties of diamond. Even an expert jeweller is unable to differentiate between diamond and strontium titanate. A ray of light is incident normally on one face of an equilateral triangular prism ABC made of strontium titanate. Answer the following questions based on the above : (a) Trace the path of the ray showing its passage through the prism. 1 (b) Find the velocity of light through the prism. 1 (c) Briefly explain two applications of total internal reflection. Z OR (c) Define total internal reflection of light. Give two conditions for it. Z Page 27 of 27