NARAYANA. C o m m o n P r a c t i c e T e s t 1 2 XII STD BATCHES [CF] Date: PHYSICS CHEMISTRY MATHEMATICS 18. (A) 33. (C) 48. (B) 63.

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1 NARAYANA I I T / N E E T A C A D E M Y. (D). (A). (D). (A). (C). (B) 7. (C) 8. (A) 9. (B) 0. (C). (B). (C). (B). (C). (D) C o m m o P r a c i c e T e s XII STD BATCES [CF] Dae: ANSWER PYSICS CEMISTRY MATEMATICS. (B). (A). (A). (A) 7. (D). (C) 7. (A). (D) 8. (A). (C) 8. (B). (A) 9. (D). (D) 9. (C). (C) 0. (D). (A) 0. (A). (B). (C). (C). (B). (A). (A) 7. (A). (C) 7. (A). (D) 8. (D). (D) 8. (C). (B) 9. (A). (C) 9. (B). (C) 0. (C). (B) 70. (C). (A). (C). (B) 7. (C) 7. (A). (B) 7. (B) 7. (B) 8. (B). (D) 8. (A) 7. (B) 9. (B). (D) 9. (D) 7. (A) 0. (C). (B) 0. (D) 7. (B) 7. (B) 77. (A) 78. (B) 79. (C) 80. (B) 8. (B) 8. (C) 8. (C) 8. (C) 8. (C) 8. (D) 87. (B) 88. (A) 89. (D) 90. (A) (i & Soluio) PART A : PYSICS. (A) The force o BC ad DE are equal ad opposie, ad cacel ou. The force o CD is BIL. (C) The Ampere force o he coducor is F Bil. The impulse give by his force o he coducor is J F d Bl i d BlQ. If u = iiial velociy, J mu BlQ.. (B) Cosider a eleme of legh o AB, a a disace from XY. I Force o he eleme df i. l 0Ii 0Ii Toal force o AB l l 7. (C) B or B si Work doe d B si mb cos 0 NARAYANA IIT/NEET ACADEMY ()

2 . (B) No work is doe i uiform circular moio. (B) mv 0 qrb qvbsi 90 i.e., v r m r r rm Bu v i.e., T T v qrb m i.e., T. qb. (C) Chage i K.E. is zero because o work is doe by mageic field. Momeum chage because direcio of velociy chages.. (D) I mageic field is speed remais uchaged. Mageic force a elecric alog egaive Y-ais, So y-co-ordiae is egaive. v u, y 0 7. (D) Usig F BIl si, we ge F 7. si BIl. 0 i.e., 0 8. (A) 0 0 W mb cos 0 cos 0 mb / 0 mb si mb si 0 mb / mb / W 9. (D) Whe he mage is be, he legh of he mage is, AC = AB + BC Lsi Lsi Lsi / 0 Lsi 0 / 0 Lsi 0 L.. (C) M M Ba d d. (A) 0 0 T M M T 0 / T MB T M M T 0 /0 9 NARAYANA IIT/NEET ACADEMY ()

3 . (D) Behaves like a paramageic maerial.. (B) Ne force o a curre carryig loop i uiform mageic field is zero. ece he loop ca raslae. So, opios (C) ad (D) are wrog. Y i F m X. (C) From Flemig s lef had rule we ca see ha if mageic field is perpedicular o paper iwards ad curre i he loop is clockwise (as show) he mageic force F m o each eleme of he loop is radially ouwards, or he loops will have a edecy o epad. F i i a ; Sice oe of he curre icreases wo imes ad disace icreases hree imes, so force becomes egaive.. (A) F v B kˆ ad da. imes. Also due o he reversal of direcio of curre force becomes 7. (A) The paricle moves i a circular pah wih radius d if i is o jus miss he wall. 8. (B) mv mv Bqr v v or B q / m sd BQr m or r v BQ As m, Q ad B are he same for all he elecros, r v. 9. (B) For a paricle movig i ay combiaio of elecric ad mageic fields, work is doe oly by he elecric field. Eergy of he paricle = work doe by he elecric field = elecric field displaceme i he direcio of he elecric field NARAYANA IIT/NEET ACADEMY ()

4 0. (C) mv p BQR Also, eergy E p / m or p me me BQR ere, he wo paricle have he same E, B ad Q / r m Or m R m m X Y R R. PART B : CEMISTRY. (D) Lacose is compoud of -D-galacose ad -D-glucose. The likage is bewee C of galacose ad C of glucose. C O O O O O C O O O O -D-Galacose O -D-Glucose. (C) The likage bewee moosaccharide ui is called glycosidic likage. 7. (A) I/Red P C O -heae+-iodoheae 8. (D) 7 K Glu cose CO C C C O O O C O (Ribose) C N N Ph Ph-N-N ( C O) C C O N N Ph (Osazoe) I deoyribose, oe O group is missig, which will preve he formaio of osazoe. 9. (A) Molisch s es is a sesiive chemical es for he presece of carbohydraes, based o he dehydraio of carbohydrae by sulphuric acid o produce a aldehyde, which codeses wih wo molecules of pheol resulig i red or purple colourd compoud NARAYANA IIT/NEET ACADEMY ()

5 0. (C) Frucise coais keoic group, while glucose coais a aldehydic group. Oly aldehydes, give posiive Beedic s reage es. Keoes do o have ay hydroge aom aached o > C = O group ad hece cao be oidized by weak oidizig age like Beedic s soluio. ece, Beedic s reage es ca be used o disiguish bewee glucose ad frucose. (B) All hose carbohydraes which coai aldehydic or keoic group i he hemiaceal or hekikeal form ad reduce Tolle s reage or Fehlig s soluio are called reducig sugars. Disaccharides like sucrose i which he wo moosaccharide uis are liked hrough heir reducig ceres, i.e., aldehydic or keoic groups are o-reducig.. (D) -malose cosiss of wo -D-glucopyraose uis wih,-glycosidic likage. C O O O O -D-glucose C O O O O O O O -D-Glucose O C O O O O O C O O O,-glycosidic likage -D-malose O. (D) I aqueous soluio, glucose eiss i all he hree forms ha is i ope chai form, pyraose form ad furaose form i equilibrium wih each oher. O. (A) emikeal group is prese i sucrose hus i does o ehibi muaroaio. 8. (B) Glucose, frucose ad maose differ oly i he cofiguraio a C ad C while res of he molecules have same sereochemisry ad hece give he same osazoe. 9. (C) Cyseie: S C C Thiol group C COO. (B) Glycie is opically iacive while all oher amio acids are opically acive. N C COO Glycie (opically iacive) NARAYANA IIT/NEET ACADEMY ()

6 . (B) I alkalie medium (high p) amio acids eis as egaively charged paricles (carboyl group doaes proos). high p N C COO N C COO 8. (A) Alaie eiss as a zwier io i eural soluio, i acidic medium, COO io of he zwier io acceps a proo o form a caio while i alkalie medium N loses a proo o form a aio. 0. (D) I p-amiobezoic acid (PABA), he loe pair of elecros o he N group is doaed owards he bezee rig. As a resul, acidic characer of COO group ad basic charger of N group decreases. Therefore, he weakly acidic COO group cao, rasfer a + io o he weakly basic N group. As a resul, PABA does eis as a zwier io. I coras, i sulphailic acid, SO group beig a much sroger acidic group ha COO group doaes a proo o weakly basic N group o form a zwier io. + N SO N SO I glycie ad alaie, o such elecro wihdrawig bezee rig is prese. As a resul, N group is sufficiely basic ad hece acceps a proo from COO group o form a zwier io.. ere, I PART C : MATEMATICS 7 7, 7/ / y dy dy I y Pu / 7/ log y C log C y log / / C k where, I a log C k From Eqs. (i) ad (ii), we ge k / a log C log C k / a ad k (i) (give) (ii) NARAYANA IIT/NEET ACADEMY ()

7 . Le Pu I a sec cos si a a.sec a sec d d d d / d d / / Pu z dz d dz a z C z. We have f f a a C a C a a co C f f d d f f log f C e f log C C e f C e f. We have he followig cases: Case I Whe 0 I his case, we have Case I Whe 0 I his case, we have C C, 0 i odd C C C NARAYANA IIT/NEET ACADEMY (7)

8 ece, C. We have, loge loge. d C C l e e e. e. We have, e e d, where e C e C 7. a a sec sec a a C A, B ad f C 8. Pla Iegraio by Subsiuio i.e. I f g. g ' g g ' d Pu I f d Descripio of Siuaio Geerally sudes ges cofused afer subsiuio, i.e. sec + a =. Now, for sec, we should use sec a ere, sec a sec a I sec a sec sec a 9/ Pu sec a sec a sec d sec. d d sec sec a sec sec.sec I sec a 9/ d. I 9/ 9/. d NARAYANA IIT/NEET ACADEMY (8)

9 K 7/ / 7 7/ / K 7sec a sec a / sec a K sec a 7 9. Le 9 9 I Now, Pu d d d I d 0 C C C e 70. Sice, I ad J e e e e J I e e Pu e u e du e e u u j I du du u u u u u du u u Pu u du d u u d log C e u log u e e C log u u e e C Le 7. Give, f I f NARAYANA IIT/NEET ACADEMY (9)

10 Pu d.(i) I f d f d f d d d C [from Eq. (i)] C si 7. Le si Pu d si d I si co d log si C ' [Iegraio by pars] log si C log log e e 7. Le I log log e e log elog e log log e e C 7. (A) Le si cos si cos si cos si cos si cos si cos si cos I c 7. Le I Pu log d d I c c log loglog NARAYANA IIT/NEET ACADEMY (0)

11 7. Le AB be he ladder of legh m. We are give, m / sec d B m h A C ABC I, AB AC BC h.(i) Differeiaig (i) w.r.., we ge 0 dh dh h (ii) d d d h d Now, from (i), whe = h h 9 h m From (ii), dh 8 d The egaive sig show ha he heigh decreases ad decreasig rae is 8 m/sec 77. Le edge of cube a da 0 cm/sec d Volume V a Differeiaig (i) w.r.., dv da dv we ge a, 0 70 cm /sec d d d f si b c f ' cos b 78. For decreasig fucio, Sice, cos, for, 79. f ' f ' 0 cos b 0 cos b b 0 f e e 80. Give a a a ' a a a f a e a e a e e for moooically decreasig fucio Sice a 0 (give) a a a e e 0. e e 0 e e a a a a f ' 0 a a 0 e e e a 0 0 a 0 8. Give curves are y 0.(i) ad y y.(ii) Differeiaig (i) w.r.., we ge dy dy y y 0 y y 0 NARAYANA IIT/NEET ACADEMY ()

12 dy y...(iii) m y Differeiaig (ii) w.r.., we ge dy dy dy y y 0 y y dy y m (iv) y mm [From (iii) & (iv)] ece,, give curves cu each oher a righ agle 8. Give ha co si si cos si cos d Also, y si cos dy cos si cos si d dy si So, (from (i) & (ii)) cos dy dy a / So he slope of he ormal is. ad a /, ad y The equaio of ormal is y y. So he disace from he origi is. dy 8. 0 e maimum = e /e 8. We have, y a b c d y ' a b c For local maimum ad local miimum we pu y ' 0 a b c 0 ere, D b a c b ac The give curve has oe local maimum ad oe local miimum if D 0 b ac 0 b ac 0 b ac, which is he required codiio. 8. f si cos f ' cos cos si f ' cos si (i) NARAYANA IIT/NEET ACADEMY ()

13 For maimum or miimum, f ' 0 cos si 0, si f " si cos.(ii) Bu, si, f " 0 f is miimum a. 8. (a, b) lie o he curve y b dy a, b a a d a b a a d d 0 da a 0 a a ab 87. dy We have, y 9 7 dy Le A slope fucio, he da da For criical pois, pu 0 0 is he criical poi, d A d A 0 So, a, slope is maimum. Maimum slope 88. Le 9 g si cos f g si cos, 0, f g ' cos si 0 a 9 NARAYANA IIT/NEET ACADEMY ()

14 g ma f mi 89. (D) lim f ad f k As f has a local miimum a f f f k k Thus k is a possible value. 90. (A) Pu = cos, y = si y cos si, TOPIC/SUB TOPIC Q. NOS. PYSICS Moio of charge paricle i mageic field,,,,,, 7, 8, 9, 0 Force o curre carryig coducor,,,,,, 8, 9,,, 7, Poeial eergy of loop i mageic field 7, 0, 8 Mageic propery of maerials 9, 0,,, CEMISTRY Carbohydrae o 8 Amio Acid 9 o 0 MATEMATICS Idefiie Iegraio 7 Rae Measure 7, 77 Icreasig decreasig 78, 79, 80 Tage Normal 8, 8 Maima Miima 8-90 NARAYANA IIT/NEET ACADEMY ()