MHT-CET 5 (PHYSICS) PHYSICS CENTERS : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPUR / BOKARO / DUBAI # 1

Transcription

1 1. (D) Givn, mass f th rckts, m = 5000 kg; Exhaust spd, v = 800 m/s Acclratin, a = 0 m/s m Lt is amunt f gas pr scnd, t Frc = m (a + g) mu m a g t m 800 m a g t m kg sc t 800 PHYSICS. (D) Frm th cnsrvatin f linar mmntum, w hav m v m v m m v v 15v v m s. (A) Givn, m r km m 7 10 rad sc Using th rlatin, w hav F mr N. (B) Givn, mass f th by, m = 0 kg, nrgy in n brad = 1 kj = 1 10 J = 1000 J Efficincy f th by = 8%; gravitatinal acclratin = 9.8 m/s Whn th fficincy f by is 8%; thn actual nrgy is cnsumd by th by is givn by J... i Th nrgy cnsumd by th by in climbing h mtr is givn by mgh 09.8 h 9 h... ii Nw aftr quating ths tw valus f nrgis frm quatins (i) and (ii), w gt 9h h 15m 9 CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI # 1

2 5. (D) Acclratin du t gravity at a hight g0 gh (Whr g0 is acclratin du t gravity at th surfac f th arth) adius f arth = 600 km Acclratin du t gravity at a hight is givn by h gh g0 1 g0 h Or g 0 1 (Whr h is th hight frm th surfac f arth) Or 1 1 h 600 h 1 Or h km 6. (B) Givn, F Kr 5/ du But F dr du Kr 5/ dr du Kr 5/ dr 5/ du Kr dr / U Kr U r / 7. (D) Angular mmntum, L p mv GM GM m 0 v0 0 0 L m GM 0 8. (B) T As w knwn that, P r And V r T 16Tr Thus PV r r CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI #

3 PV r 9. (C) Givn, mass f th bdy, m = 00 gm = 0. kg, hight, h = 00 m, g = 10 m/s Ptntial nrgy f th bdy is givn by UP mgh J 10. (B) Vlcity at th tp = 00 cs 60 = 100 m/s Nw applying th law f cnsrvatin f linar mmntum w find that th particls ging upwards and dwnwards shuld hav qual mmntum. Thus, th initial mmntum f th cmpsit particl is transfrrd t th third particl. m m 100 v Hnc, v = 00 m/s 11. (D) Mmnt f inrtia, 1 I m kg m 1. (D) Givn, initial vlcity u = 0, distanc travlld, s = 10 cm = 1. m, Numbr f scnd, n = 8 Th distanc travlld by th bdy is givn by a sn ut n 1 a a m s a (D) Givn, dpth f lak = 00 m, dcrass in vlum f ball = 0.1% Bulk mdulus is givn by p hg B V V N m 1. (B) Givn, hight f th fall = 500 m, spcific hat f watr, c =. kj/kg, CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI #

4 Ptntial nrgy = Hat incrasd in watr mgh mc gh C c (C) Frquncy f clsd rgan pip is half that f pn rgan pip npn ncls Whn pn pip is dippd in watr upt half its lngth, thn it will bhav lik a cls pip f half lngth. Frquncy f pip is invrsly prprtinal t its lngth. npn Nw frquncy, n npn n frquncy rmains sam r f f 16. (C) Givn, frquncy f = 500 Hz, vlcity v = 50 m/s, phas v 50 By th frmula, 0.7m f 500 Als w knw that x mtr 1 cm (D) Frm d-brgli thry th wavlngth Plancks cnstant Mmntum Hnc, if m mmntum is dubld, thn d-brgli will b halvd. 18. (B) Givn, frquncy f wav, n = 100 Hz, Distanc 10 cm 0 cm Frm th frmula, w hav v n cm sc 0 m s 19. (C) Givn, vlcity f surc, v 0 km hr, actual frquncy f sund, 000 Hz, vlcity f sund 10 km hr Frm th Dpplr s ffct, whn th surc is travlling twards th bsrvr, thn apparnt frquncy is givn by v ' v v' CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI #

5 Hz 068 Hz 0. (B) Givn, magnitud f th first vctr, A, Magnitud f th scnd vctr, B 5 and angl btwn thm, Th dt prducts f tw vctrs is givn by A.B A Bcs 5cs (B) As w knw, Trqu = frc distanc Hnc, dimnsins f trqu = dimnsins f frc dimnsins f distanc = [MLT ] [L] = [ML T ]. (C) Givn, lngth f th rd, I = 0 cm = 0. m Frquncy, 000 Hz Lngth f th rd, L 0. Or m Hnc, th vlcity f sund in gas is givn by v m s. (A) Givn, critical angl, C = 0 Accrding t law f ttal intrnal rflctin, Vlcity f light in mdium sin C Vlcity f light f air Vlcity f light in mdium sin 0 Vlcity f light f air Thus, vlcity f light in mdium = vlcity f light in air m s. (B) Givn, mass f th plant. M MP (whr is th radius f th arth) 9 Wight f bdy n th arth, w 50 N Accrding th law f gravitatin th wight f th bdy (r frc f gravity) GMm M w CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI # 5

6 w M P Hnc, w p M p (Whr w is th wight n th plant) Or p p 50 M w M p p 9 50 w 00 N 9 5. (D) Lt th tmpratur f th mixtur b Hat givn by xygn nc T v Hat rcivd by nitrgn nc T v Thus C But 6. (D) In th systm, whr Q 0 it mans n hat ntrs r lavs in a systm during th prcss. This prcss is calld adiabatic prcss. 7. (B) If cnstant prssur, V T V T V T V T T T T T T T T T U C T T PV 1 T v 8. (B) Accrding t Sttan s law th ttal radiant nrgy CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI # 6

7 Q CA T T Q 1 Q T Hnc,... i Q1 T1 Q and T K Frm quatin (i), T / 1/ T 1000 T K 9. (B) Gain in kintic nrgy = wrk But, wrk Fscs q E y cs qey 0. (C) Lt fur capacitanc ar cnnctd in paralll capacitanc f ach capacitr = C 6 C 5 10 farad V 00 vlt Charg n ach capacitr, Q CV culmb 1. (A) Th pwr f hatr is givn by, V 110 P W 10. (A) As w knw, dw 0 p MH sin d cs p 0 cs MH MH 1. (A r C) Hat prducd is rsistanc f wir 0 vltag V 10 V CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI # 7

8 V 10 Hat prducd, H t 1 0 Hat rquird fr ic t mlt = ml But 10 1 ml 0 Hnc, 10 1 m m g s. (C) Th intrnal rsistanc ar cnnctd in paralll s th quivalnt rsistanc is 11 1 rq Nw, currnt passing thrugh is E i amp r Pwr is givn by 5. (B) P i W Fr a thin prism, dviatin D Whn th prism is placd in air, thn a D 1 A 0 p I A A 1 A... i Whn th prism is dippd in watr, thn a w 0 Dw q 1 A 1 A a w 9 1 A 1 A 8 A... ii 8 A Dw 1 Thrfr, 8 D A n 6. (A) Accrding t Bhr s thry, vlcity f th lctrn in th innrmst rbit is highst. CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI # 8

9 7. (C) Limit f rslutin f tlscp radian d sc 5 0.0scnd 8. (C) As w knw, nrgy f pht lctrns, hc E h E jul V V 8 1 Nw, h mvmax 1 mv max h V 9. (A) adius f a nuclus changs with nucln numbr A f th nuclus as 15 1/ A m 1/ A Hnc, 1/ A 1 1 1/ 8 1/ 1 1 Thrfr, radius f sulphur nuclus is largr than that f hlium by factr f. 0. (A) Givn, 0.95, IE 100 ma Ic 0.95 IE I c I c 95 ma CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI # 9

10 1. (C) Currnt acrss 0 rsistr is 0.8 A. Currnt thrugh th paralll rsistanc f A 6 Ttal currnt acrss A Nw ptntial drp acrss rsistr 1..8 V. (D) Whn th pl f a bar magnt is pinting in th nrth dirctin, th magntic lins pass thrugh th magnt and th null pint li n th quatrial-lin f bar magnt.. (D).m.f. f first battry, E1 V.m.f. f scnd battry, E = 8 V Intrnal rsistanc f first battry, r 1 1 Intrnal rsistanc f scnd battry, r Circuit rsistanc, 9 Frm th Kirchhff s currnt law, w hav ir i ir i1 i9 i 8 0 r 1i 1 r i A 1 Nw ptntial diffrnc acrss PQ, 1 VlPQ i 9 V. (A) Mass f th bullt, m = g = 0.0 kg Initial vlcity u = 10 m/s Distanc travlld by th bullt, s = 1 cm = 0.1 m latin fr th final vlcity is givn by v u as v u as Or 0 10 a Or a 0. Hnc, rsistanc xrtd by th blck, F ma N m s (minus sign rprsnts rtardatin f bullt) 5. (C) Magntic mmnt f bar magnt, M 0 A m Magntic fild intnsity, H 0.5 N A m CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI # 10

11 Angl f dflctin, 0 Cupl rquird t dflct th magnt M H sin sin 0 5 Nm 6. (C) Magntic mmnt f ach magntic, M1 M M Sinc tw magntic mmnts ar placd prpndicular t ach thr, hnc, nt magntic mmnt M M M M 1 7. (B) Distanc btwn tw atms.7å d.7 Atmic radius, r 1.85Å Nw, atmic radius, r a Whr, a lattic paramtr r 1.85 a 1.85 a.7å.å 8. (A) Whn th wavs which scillats prpndicularly t th dirctin f prpagatin ar knwn as th transvrs wavs and als th transvrs wavs can b prducd in slids ths which ar having sm rigidly. As w knw that th gass d nt hav any rigidly. Thrfr, transvrs wavs can nt b prducd in gass. 9. (B) Displacmnt, x a 0 a1t a t Vlcity f th particl, dx da0 a1t a t v dt dt a1 a t Acclratin f th particl, dv d a1 a t a dt dt a a 50. (B) Bcaus f air rsistanc is takn int cnsidratin s th hrizntal vlcity f th bmb is dcrasd, whil th arplan is mving with cnstant spd. Nw it is clar that bmb will fall n th arth bhind th arplan. CENTES : MUMBAI /DELHI /AKOLA /LUCKNOW / NASHIK /PUNE /NAGPU / BOKAO / DUBAI # 11