Due to both the rings the magnetic field will be in same direction B = 0 i

Transcription

1 Q. No. 1 A wire is formed into shpe of two hlf circles connected by equl length sections s shown if figure. A current flows in circuit clockwise s shown. Wht is the mgnitude of the mgnetic field induction t the centre (R 1 R )I (R R ) 1 Option R R 1 )I R R 1 (R 1 R )I R R 1 Option (R 1 R )I R R Correct Answer 3 1 Due to both the rings the mgnetic field will be in sme direction B i r For Bnet i i B net + R R 1 I R +R R R 1 1 Q. No. Consider current crrying loop shown in figure formed by rdil lines nd segments of circle whose centers re t point P. wht is the mgnitudes of mgnetic field induction t point P. I b Option I b

2 I b Option I 1 1 b Correct Answer 3 dl rd By biot svrt lw idlsin B v For ny loop, idlsin9 db r db d r 3 rd d i i i B r r 3 1r i 1 1 B net 1 b r Q. No. 3 The unit vectorsî,ĵnd ˆkre s shown below. Wht will be the mgnetic field t O in the following figure i ˆj Option i + ˆj i + ˆi Option i + kˆ Correct Answer

3 The wire cn be considered to be mde of two semi infinite wire nd one curved wire. I I B semi infinite + And lso i B curved r As ll fields re in sme direction we get I i B net + i + k Q. No. In figure, the conductors crry equl currents I. All stright segments re very long nd two circulr loops hve equl rdil. However current round loops hve opposite scenes. wht is the rtio of mgnetic fields t nd b t the centre of the loops. B +1 B 1 Option B + B B 1 B +1 Option B +1 B b b b b i i i 1+ B + r r r

4 i i i 1 B b r r r B +1 B 1 b Q. No. 5 A current iflows through n infinitely long wire hving infinite bends s shown. The rdius of first curved section is nd the rdil of successive curved portions ech increses by fctor. The mgnetic field t the point O is Option Option i +1) i +1) i +1) i 1) Correct Answer Field due to ny wire depends on B i r When r is distnce of wire. Let B due to first be i B 1 Similrly for other rings i B i i i B net +... i i i

5 i i 1 +1 i +1 Q. No. 6 A circulr current crrying coil hs rdius R. the distnce from the centre of the coil on the xis where the mgnetic induction will be 1/8 th to its vlue t centre of the coil, is R/ 3 Option R 3 3 R Option R / 3 Correct Answer IR B x +R I B R 3 1 I IR 8 R x +R 3 3 x +R 8R 3 x +R R x 3R x 3R

6 Q. No. 7 The mgnetic field t the centre of circulr coil of rdius r is times tht due to long stright wire t distnce r from it, for equl currents, figure here shows three cses: in ll cses the circulr prt hs rdius r nd stright ones re infinitely long. For sme current the B field t the centre P in cses, 1,, 3 hve the rtio 1 : : + Option 1 +1 : +1 : + : :3 Option : : + B i r i i i i B 1 + r r r r B i r i 3 i i 3 B r r r 1 3 B 1:B :B 3 1:1: 1 : :3 Q. No. 8 A non conducting ring with rdius of 1 cm is uniformly chrged with totl positive chrge of 1 C. the ring rottes t constnt ngulr speed of rd/s bout n xis pssing through its centre perpendiculr to plne of the ring. Wht is mgnitude of the mgnetic field on the xis of the ring t 5cm from the centre? 13 pt Option 1 pt 9 pt Option pt For ring

7 i q q B Also i 3 + x t 7 6 q x pt 13 3 Q. No. 9 The rtio of the mgnetic field t the centre of current crrying circulr wire nd the mgnetic field t center of squre coil mde from the sme length of wire will be Option 8 Option 1 Correct Answer i B circulr wire Also r l r r l For every side of squre i B sin 1 +sin i r i B Net l i Bcirculr r l Bsqure i r 8 l

8 Q. No. 1 Wht is the vlue of the mgnetic field induction t the point Pmentioned in the figure? I + R d Option I 3 + R d I 3 3 R d Option I R d i i i 3 B Net sin 1 +sin + sin +sin + R d d i 1 i 1 i R d d 3 i + d d Q. No. 11 In the give figure net mgnetic field t O will be Option I 3 I 3 + +

9 Option I 3 I 3 Correct Answer Due to loops i i B j 3 i j 3 Due to wires i i B j j + 3 i k 3 i i B Net j k 3 3 i i B j Q. No. 13 Two circulr coils X nd Y hve equl number of turns nd crry equl currents in the sme sense nd subtend sme ngle t point O, if the smller coil X is midwy between O nd Y, nd we represent the mgnetic field due to coil Y nd O s B y nd tht due to smller coil X nd O s B x then B y 1 B Option B y B x x

10 By 1 B Option By 1 Bx Correct Answer 3 Rx Rx d d x R y R x R R i i x y B x B y R + x R + x B B y x R R 3 3 x x R R + i x x x. R + x irx x x x 3 Rx Rx 8 B : B : 1: 3 3 y x Q. No. 1 The mgnetic field due to stright conductor of uniform cross section of rdius nd crrying stedy current is represented by Option

11 Option Conceptul Q. No. 15 Wht is the mgnetic field t O due to current crrying long wire, forming loop s shown in figure? I downwrds Option 3I outwrds I outwrds Option 3I downwrds Correct Answer i B 1 sin17sin5 i i i B sin5+ sin5 i B net 3i downwrds

12 Q. No. 16 Two thick wires ndtwo thin wires, ll of the sme mterils nd sme length form squre in the three different wys p, Q nd R s shown in figure with current connection shown, the mgnetic field t the centre of the squre is zero in cses In P only Option In P nd Q only In Q nd R only Option P nd R only Correct Answer Conceptul Q. No. 17 Two long prllel wires crry currents I 1 3. A nd I 3. A, both directed into the plne of pper. Wht is the mgnitude of mgnetic field induction t the point p. Option Option Correct Answer 7.5 T T 3 T 13 T

13 7 i 1 3 B 1T r i 1 3 B 5T r 11 B T Net Q. No. 18 AB nd CD re long stright conduction, distnce d prt, crrying current I. the mgnetic field t the midpoint of BC is I k d Option I k d I k d Option I k 8d Correct Answer i B sin +sin d i B i d d B i Net k d 1 Q. No. A current i is flowing in stright conductor of length L. the mgnetic induction t

14 Option point distntl/ from its centre will be i 5L i L i L Option Zero i B sin 1+sin d i + L 5 5 i 5 L Q. No. 1 Mgnetic field t the origin due to current flowing in wire s shown in figure below is I ( i+ k) 8 Option I ( i + k ) I ( i + k ) 8 Option I ( i+ k) Correct Answer 3 i B i

15 B Bcos k Bsin i i 1 i 1 B i ( i+ k) 8 Q. No. In the following figure wire bent in the form of regulr polygon of n sides is inscribed in circle of rdius. Net mgnetic field t centre will be I tn n Option ni tn n ni tn n Option ni tn n Correct Answer For single side i B sin +sin d i sin 9cos 1 n i tn 9cos n Q. No. 3 Which of the following grphs shows the vrition of mgnetic induction B with distnce r from long wire crrying current

16 Option Option Correct Answer 3 Conceptul Q. No. Two infinite length wires crries currents 8A nd 6A respectively nd plced long X nd Y xis. Mgnetic field t point p(,, d)m will be 7 d Option 1 d 1 d

17 Option 5 d Correct Answer i 8 Bx i d d i 6 3 By i d d Net B + d d d 5 B Net d Q. No. 5 Current I 1 nd I flows in wires shown in figure. The field is zero t distnce d to the right of origin O. then I1 d I Option I d I 1 I1 I d I 1 +I Option I +I1 d I 1 +I Correct Answer 3 B i1 1 + d i B d i1 i + d d 1 I + d I d

18 I 1+I d I I 1 I I d I +I 1 1

19 Q. No. 6 Figure shows squre loop ABCD with edge length. the resistnce of the wire ABC is r nd tht of ADC is r. the vlue of mgnetic field t the centre of the loop ssuming uniform wire is i 3 Option i 3 i Option i Correct Answer R r R r ABC ADC i i i 1 i 3 3 i B sin +sin d i B AB 3 i 3 1 B i ABC 3 i B ADC 3 i 3 i i B Net i 3

20 Q. No. 7 A wire is bent into shpe s shown in figure nd mgnetic field is mesured t P 1 when current in wire is I, the sme wire is then formed into shpe shown in figure. Mgnetic field is mesured t P when current is gin I. if totl length of the wire is sme in ech cse. Wht is rtion of B 1 to B. I Option Option 16 5 Correct Answer 3 For figure 1 i 1 B i Net + i i i i i + r r r For figure B i i r r rl B i 16 l B1 i 16l 8. B l i Q. No. 8 Two infinitely long stright wires lie in the x y plne long x nd y xis respectively. Ech wire crries current I, respectively in positive direction of x nd y xis. The locus of points, where the mgnetic field is zero is y x Option x y x y Option x + y Correct Answer 3

21 + i + i y x x y Q. No. 9 Two wires AO nd OC crry equl currents I s shown. AOC. The mgnitude of mgnetic field t the point p on the bisector of ngle t distnce r from point O is (ssume one end of both wire extends to infinity) i cot r Option i cot r i 1+cos / r sin / Option i cot r Correct Answer 3 d rsin i B cos rsin

22 i cot r B i cot r Q. No. 3 A long stright wire, crrying current I is bent t its mid point to form n ngle of 5.At point P. distnce R from the point of bending. The mgnetic field is 1 r Option +1 r +1 R Option 1 R i i i i i B sin 1+sin d i 1+sin 5 R 1 i 1 R 1 R i Q. No. 31 Infinite number of stright wires ech crrying current I re eqully plced s shown. djcent wires hve current in opposite direction. Distnce between the wires is equl to distnce between first wire nd P. net mgnetic field t point p is

23 Option Option Zero n i l k 3 n i l k 3 n i l ( k) 3 I B sin 1+sin d I I B 1 1 B I B Net I I lnk 3 Q. No. 3 Two very thin metllic wires plced long X nd Y xis crry equl currents s shown here. AB nd CD re lines t 5 with the xes with origin of xes t O. the mgnetic field will be zero on the line AB

24 Option CD Segment OB only of line AB Option Segments OC only of line CD Conceptul Q. No. 33 Wht will be the resultnt mgnetic field t origin due to four infinite length wires. If ech wire produces mgnetic field B t origin Option B B B Option zero Correct Answer 3 Due to wire on y xis Net mgnetic field will be B. Due to wire on x xis it will be B. B Net B +B B Q. No. 3 A long thin hollow metllic cylinder of rdius R hs current I mpere. The mgnetic induction B wy from the xis t distnce r from the xis vries s shown in Option

25 Option Conceptul Q. No. 35 Figure shows the cross sectionl view of the hollow cylindricl conductor with inner rdius R nd outer rdius R cylinder crrying uniformly distributed current long its xis. The mgnetic induction t point P t distnce 3R/ from the xis of the cylinder will be Zero Option 5i 7R 7i 18R Option 5i 36R Correct Answer B dl I 3R i B rdr R R 3BR i r 3R i 9R 3BR R 3R 5 3BR i 1 B 5 i 36 R 3R R

26 Q. No. 36 The correct curve between the mgnetic induction (B) long the xis of long solenoid due to current flow I in it nd distnce x from one end is Option Option Conceptul Q. No. 37 A 1 turn closely wound circulr coil of rdius 1 cm crries current of 3. mpere. The moment of inerti of the coil is.1 kgm. The coil is plce in verticl plne nd is free to rotte bout horizontl xis which coincides with its dimeter. A uniform mgnetic field of. T in horizontl direction exists such tht plne of the coil is prllel to field. The coil rottes through n ngle of 9 due to torque. Wht is the ngulr speed cquired by the coil when it hs rotted by 9 1 rd/s Option 15 rd/s rd/s Option 5 rd/s Correct Answer 3

27 1 B I 1 ni r B I rd / s Q. No. 38 A proton (mss m nd chrge +e) nd n prticle (mss m nd chrge +e) re projected with the sme kinetic energy t right ngles to the uniform mgnetic field. Which one of the following sttements will be true The prticle will bent in circulr pth with smll rdius tht tht for the protion Option The rdius of the pth of the prticle will be greter thn tht of the proton The prticle nd the proton will be bent in circulr pth with the sme rdius Option The prticle nd the proton will go through the field in stright line Correct Answer 3 Conceptul Q. No. 39 If proton, deuteron nd prticle on being ccelerted by the sme potentil difference, enter perpendiculr to the mgnetic field, then the rtio of their kinetic energies is 1:: Option ::1 1::1 Option 1:1: Correct Answer KE p :KE d :KE α 9 p :9 d :9α 1:1: Q. No. An electron nd proton enter region of uniform mgnetic field in direction t right ngles to the field with the sme kinetic energy. They describe circulr pths of rdius r e nd r p respectively. then r e r p Option r e! r p r e " r p Option r e my be less thn or greter thn r p depending on the direction of the mgnetic field Correct Answer Conceptul Q. No. 1 A prticle of chrge q nd mss m moving with velocity v long the x xis enters the region x " with uniform mgnetic field B long the ˆk direction. The prticle will penetrte in this region in the x direction upto distnce d equl to

28 Option Zero mv qb mv qb Option Infinity Correct Answer mv qvb r mv d qb Q. No. Two ions hving msses in the rtio 1:1 nd chrges 1: re projected into uniform mgnetic field perpendiculr to the field with speeds in the rtio :3 the rtio of the rdil of circulr pths long which the two prticles move is # 3 Option # 3 3# 1 Option 1# For prticle 1 nd mv r1 m1v1 qb r. qb r mv q1b1. 3 r 1:r :3 Q. No. 3 There is mgnetic field cting perpendiculr to plne of pper inwrds. Prticles in vcuum move in the plne of pper from left to right s shown. The pths re numbered s 1 to 3. which sttement is wrong. I could be n prticle s pth Option is for neutron 3 is for n electron Option 3 is for proton Correct Answer Conceptul Q. No. An electron (q C) is moving t right ngle to the uniform mgnetic field T. the time tken by the electron to complete circulr orbit is s

29 Option s 3s Option 1s Correct Answer r mv T nd r v q B 31 m qb s 9 5 Q. No. 5 A prticle of chrge per unit mss is relesed from origin with velocity of v v i in uniform mgnetic fieldbb k. If the prticle psses through point p (, y, ) nd then y is equl to v B Option v B v B Option v B Correct Answer 3 We know mv r q B y v B v y B Q. No. 7 A prticle with chrge q, moving with momentum p, enters uniform mgnetic field normlly. The mgnetic field hs mgnitude b nd is confined to region of width d, P whered!, the prticle is deflected by n ngle in crossing the field Bq Bqd sin p

30 Option Option P sin Bqd Bq sin qd pd sin Bq From Figure R sin d d dqb sin R mv Q. No. 8 A bem of singly ionized toms of crbon ech chrge +e ll hve the sme speed nd enter mss spectrometer, s shown in figure. The ions strike the photogrphic plte 1 in two different loctions 5 cm prt. The 6 Cisotope trces pth of smller rdius, 15 cm. wht is tomic mss number of other isotope? 1 Option Option 18

31 r$ m r m r m % m 35 m 15 m 1 Q. No. 9 A proton ccelerted by potentil difference 5 kv moves though trnsverse mgnetic field of.51 T s shown in figure. The ngle through which the proton devites from the initil direction of its motion is 15 Option 3 5 Option 6 Correct Answer We know Bqd sin mv Bqd sin mqv 1 We know qv mv mv mqv sin o

32 Q. No. 5 An electron is moving long the positive X xis. you wnt to pply mgnetic field for short time so tht the electron my reverse its direction nd move prllel to the negtive X xis. This cn be done by pplying the mgnetic field long. Y xis Option X xis Y xis only Option None of these Conceptul Q. No. 51 If chrge prticle goes with uniform velocity in region contining electric nd mgnetic fields E must be perpendiculr to B Option v must not be perpendiculr to E v must be perpendiculr to B Option E must be equl to v B The forces should get cncelled Q. No. 5 A chrge prticle is projected in the mgnetic field of 6i 5j 3 1 T. The ccelertion of the prticle is found to be i+6 j 6 1 ms. the vlue of is 5 Option 6 1 Option 1 The ccelertion of prticle nd mgnetic field re perpendiculr to ech other. 6i 5 3 j 1. i+6 6 j Q. No. 59 A conducting rod of length I nd mss m is moved down smooth inclined plne of inclintion with constnt velocity v. A current I is flowing in the conductor in the Option direction perpendiculr to pper inwrds. A verticlly upwrds mgnetic field B exists in spce. Then the mgnitude of the mgnetic field will be mgsin il mg tn il

33 Option mgcos il mg il Correct Answer As rod is moving with constnt velocity mgsin il Bcos mgtn B il Q. No. 61 In the rrngement shown in figure, the force cting on strgigh wire crrying current I plced between north pole nd south pole of mgnets is, the mgnetic field strength is B, Option Option BI Zero BI BI Direct Formul Q. No. 6 An elstic circulr wirre of lengthicrries current i. it is plced in uniform mgnetic field B (out of pper) such tht its plne is perpendiculr to the direction of B. The wire will experience

34 No force Option A stretching force A compressive force Option A torque Correct Answer conceptul Q. No. 6 A uniform conducting wire ABC hs mss of 1g. A current of A flows through it. The wire is kept in uniform mgnetic field B T. the ccelertion of the wire will be Option Zero 1ms longy xis ms long y & xis Option ms longy & xis Correct Answer Along x xis F 1+F cos m m 5 Along y xis F sin m il Bsin m

35 1ms Q. No. 65 A conducting wire bent in the form of prbol y x crries current of I A s shown in figure. The wire is plced in uniform mgnetic field B k tesl. The mgnetic force on wire in newton is 16 i Option 3i 16 j Option 3i Correct Answer By using concept of projected length F Net ilb 3 Q. No. 66 A wire crrying current is plced in uniform mgnetic field in the form of the curve y sin ( π x /L) ' x 'L. ' The force cting on the wire is ibl Option ibl ibl Option Zero Correct Answer 3

36 The totl projected length is L By symmetry F ilb Net F ilb Net Q. No. 67 A conducting rod of mss m nd length I is plced over smooth horizontl surfce. A uniform mgnetic field B I cting perpendiculr to rod. Chrge q suddenly psses through the rod nd it cquires n initil velocity of v on the surfce, then q is equl to mv Bl Option mv Bl Blv m Option mv Bl Correct Answer As chrge moves suddenly the current will be produced As rod is initilly t rest mv F.t. mvilb.t t l ndi q v t q mv. lb.t t q mv lb Q. No. 68 A current crrying loop is plced in uniform mgnetic field. The torque cting on it does not depend upon Shpe of the loop Option Are of the loop

37 Vlue of the current Option Mgnetic field Conceptul Q. No. 69 A rectngulr loop crrying current iis plced in uniform mgnetic field B. The re enclosed by the loop is A. If there re n turns in the loop, the torque cting on the loop is given by nia B Option nia( B 1 (ia B) n Option 1 (ia ( B) n Fctul Q. No. 7 A current crrying rectngulr coil is plced in uniform mgnetic field. In which orienttion, the coil will not tend to rotte The mgnetic field is prllel to the plne of the coil Option The mgnetic field is perpendiculr to the plne of the coil The mgnetic field is t 5 with the plne of the coil Option Alwys in ny orienttion Correct Answer ). ia B *to plne of loop. Q. No. 71 A rectngulr coil cmcmhs 1 turns nd crries current of 1A. It is plced in uniform mgnetic field B.5 T with the direction of mgnetic field prllel to the plne of the coil. The mgnitude of the torque required to hold this coil in this position is Zero Option N m N m Option 1 N m Correct Answer 3 Torque cting on rectngulr loop. ) nia B Nm Q. No. 7 A flt disc of rdius R crries n excess chrge on its surfce. The surfce chrge

38 density is+. The disc rottes bout n xis perpendiculr to its plne pssing through the centre with ngulr velocity. Wht torque will ct on the disc if it is plced in uniform mgnetic field B directed perpendiculr to the rottionl xis. + BR Option + BR + BR 3 3 Option + BR Correct Answer ) ia B iabsin iab q + R + R i t + R R B iab +. R.B ) Q. No. 73 The ) grph for current crrying coil plced in uniform mgnetic field B where is torque mgnitude on coil nd is the ngle mde by A ndb. Option

39 Option Conceptul Q. No. 7 A wire of length L metre crrying current of I mpere is bent in the form of circle. Its mgnitude of mgnetic moment will be IL Option IL I L Option I L Correct Answer Mgnetic moment IA IR L I IL Q. No. 75 The mgnetic moment of n electron in nth orbit of hydrogen tom is neh m Option neh m neh m Option meh n Option 5

40 Option 6 Correct Answer 3 We know nh nh mvr % vr m ev evr i r. r r neh m Q. No. 76 A thin circulr wire crrying current I hs mgnetic moment M. The shpe of the wire is chnged to squre nd it crries the sme current. It will hve mgnetic moment M Option M M Option M Correct Answer M R I R M I AlsoRL M L R. I squre M IL I Q. No. 77 The current flowing in circulr loop of cross section m is 3 A. If the direction of the current is reversed keeping the mgnitude sme, then chnge in mgnetic moment is 1 Am Option 6 Am 1 Am Option Zero Option 5 Option 6 1 IA6Am

41 IA 6Am 1, 1 1Am Q. No. 78 A ring of rdius R, mde of n insulting mteril crries chrge Q uniformly distributed on it. If the ring rottes bout the xis pssing through its centre nd norml to plne of the ring with constnt ngulr speed, then the mgnitude of the mgnetic moment of the ring is QR Option 1 Q R Q R Option 1 Q R Correct Answer IA Q R 1 QR Q. No. 79 A long wire AB is plced on tble. Another wire PQ of mss 1. g nd length 5 cm is set to slide on two rils PS nd QR. A current of 5 A is pssed through the wires. At wht distnce bove AB, will the wire PQ be in equilibrium due to AB 5 mm Option 5 mm 75 mm Option 1 mm For equilibrium ilbmg il i mg d

42 il d mg mm Q. No. 8 A long stright wire crries current of mpere s shown. A rectngulr coil with two sides prllel to stright wire hs sides 5 cm nd 1 cm with ner side distnce of cm from wire. The coil crries current of 5 mpere. Clculte net force on the coil due to wire Ntowrds right Option.71 1 Ntowrds right.3 1 Ntowrds left Option Ntowrds left Correct Answer B. i d F il B il B Net 1 1 i towrds right Q. No. 81 An infinitely long, stright conductor AB is fixed nd current is pssed through it. Another movble stright wire CD of finite length nd crrying current is held perpendiculr to it nd relesed. Neglect weight of the wire

43 The rod CD will move upwrd prllel to itself Option The rod CD will move downwrd prllel to itself The rod CD will move upwrd nd turn clockwise t the sme time Option The rod CD will move upwrd nd turn nti clockwise t the sme time Correct Answer 3 Conceptul Q. No. 8 A smll circulr flexible loop of wire of rdius r crries current I. It is plced in uniform mgnetic field B. the tension in the loop will be double if current I is doubled Option Mgnetic field B is Doubled rdius r is doubled Option both mgnetic field B nd current I re doubled The force (Tension) depends on mgnitude of current nd mgnetic field Q. No. 83 A long stright wire crries current long x xis. Consider the points P(,1,), Q(,1,1), R(1,,1) nd S(1,1,1). Which of the following pirs of points will hve mgnetic fields of the sme mgnitude. P nd Q Option P nd R Q nd R Option Q nd S

44 B i d B$ d P nd R, Q nd S will hve sme mgnitude of mgnetic field Q. No. 8 Velocity nd ccelertion vector of chrged prticle moving in mgnetic field t some instnt re v3i+3j nd ccelertion i+x j then select the correct option. x 1.5 Option x mgnetic field is long Z xis Option speed of the prticle is constnt As ptrice moving in mgnetic field FqvB v * % prticle moving with constnt speed v. %6+ 3x % x As F* B the mgnetic field should be long z xis Q. No. 85 An equilterl tringulr loop PQR of side length L crries current in the shown direction. The loop is kept in uniform horizontl mgnetic field B prllel to bse QR.. Then net force on loop is zero Option perpendiculr to its plne inwrds perpendiculr to its plne outwrds Option 3BIL

45 Bsin. F Net il1bsin ilbsin Q. No. 86 The cyclotron frequency is independent of mss of the prticle Option speed of the prticle rdius of circulr pth of prticle Option chrge of the prticle Bq - m conceptul Q. No. 87 When current crrying coil is plced in uniform mgnetic field with its mgnetic moment ntiprllel to mgnetic field Torque on it will be mximum Option Torque on it is zero potentil energy is mximum Option dipole is in unstble equilibrium ) B P.E. B Q. No. 88 Two ions hve equl msses but one is singly ionized nd the other is doubly ionized. They re projected from the sme plce in uniform mgnetic field with the sme velocity perpendiculr to the field Both ions will go long circles of equl rdii Option Two circles touch ech other The circle described by singly ionized chrge will be double rdius to tht of other circle Option The two circles do not touch ech other. mv 1 r r1 $ qb q r1 q1 % r 1:r :1 r q Q. No. 89 If chrged prticle kept t rest experience n electromgnetic force then The electric field must not be zero Option Mgnetic field must not be zero

46 Electric field my or my not be zero Option The mgnetic field my or my not be zero For mgnetic field to come into picture the prticles should be electricl field. Hence,d re correct. Q. No. 9 An electron is moving long positive x xis. You wnt to pply mgnetic field for short time so tht electron my reverse its direction nd move prllel to negtive x xis. This cn be done by pplying the mgnetic field long y xis Option z xis y xis only Option z xis only conceptul Q. No. 91 A chrged prticle moves in uniform mgnetic field. The velocity of the prticle t some instnt mkes n cute ngle with mgnetic field. The pth of the prticle will be A helix of uniform pitch Option A spirl of incresing rdius A helix of uniform rdius Option Helix with incresing pitch mvsin r qb Pitch vcos t Q. No. 9 A hollow tube is crrying n electric current long its length distributed uniformly over its surfce. The mgnetic field increses linerly from xis to surfce Option is constnt inside the tube is zero t the xis Option is non zero outside the tube conceptul Q. No. 93 When current in circulr loop is equivlently replced by mgnetic dipole the mgnetic dipole, moment ssocited with it depends upon Orienttion of the loop Option Current in the loop Are of the loop Option None of these conceptul Q. No. 9 A compss needle which is llowed to move in horizontl plne is tken to n erth mgnetic pole. Which of the followings re wrong? needle will sty in north south direction only

47 Option needle will sty in est west direction only needle will sty in ny position Option needle will become rigid showing no movement Fctul Q. No. 95 Which of the following mgnetic mterils re ffected by the chnge in their temperture? Dimgnetic Option Prmgnetic Ferromgnetic Option All of these Fctul Q. No. 96 Which of the following sttements re correct? Dimgnetism occur in ll mteril Option Dimgnetism is produced due to prtil lignment of permnent mgnetic dipoles Mgnetic field of induced mgnetism is opposite to pplied field Option Ferromgnetism is produced due to domin formtion nd their lignment in externl mgnetic field Fctul Q. No. 97 A flt circulr coil crrying current hs mgnetic moment M M hs no direction Option The direction of M is long the norml to plne of coil The direction of M depends on direction of current flow Option The direction of M will not chnge if current is reversed IA Conceptul Q. No. 98 Current crrying ring is plced in mgnetic field. The direction of field is perpendiculr to the plne of the ring. There is no force on the ring Option The ring will tend to expnd The ring will tend to contrct Option Either b or c depending on current direction Conceptul Q. No. 99 Two identicl chrged prticles enter into uniform mgnetic field with sme speed but t ngle 3 nd 6 with field. Let, b nd c be the rtio of their time periods, rdii nd pitches of helicl pth respectively then bc 1 Option bc >1 bc <1 Option bc We know

48 m mvsin m T r pitch p vcos qb qb qb Let prticle 1 mkes ngle 3 o. nd mkes 6 T 1 r 1 1 sin3 p1 cos3 b c T r sin6 p cos6 bc 1nd bc Q. No. 1 The mgnetic field inside stright solenoid is independent of rdius of solenoid Option depends on number of turns nd current in solenoid is uniform throughout the solenoid Option is perpendiculr to xis of the solenoid Conceptul Q. No. 11 A proton is fired from origin with velocity vv j+vk in uniform mgnetic field BB j. In the subsequent motion of the proton its Z coordinte cnnot be negtive Option its x coordinte cn not be positive its x nd z coordinte cnnot be zero simultneously Option Its y coordinte will be proportionte to its time of flight Conceptul Q. No. 13 A long conductor of rdius R crries current uniformly distributed over its cross section The mgnetic field strength is mximum on the surfce Option The mgnetic field strength is zero on the surfce The strength of the mgnetic field inside the cylinder will vry s directly proportionl to r, where r is the distnce from the xis. Option The energy density of the mgnetic field outside the conductor vries s inversely proportionl 1/r, where r is the distnce from the xis. Conceptul Q. No. 1 A chrge prticle of chrge q, mss m is moving with initil velocity v s shown in figure in uniform mgnetic field Bk. Select the correct lterntive / lterntives

49 Option1 Velocity of prticle when it comes out from mgnetic field is vvcos3 i vsin3 j Option m Time for which the prticle ws in mgnetic field is 3qB mv Distnce trvelled in mgnetic field is 3qB Option The prticle will never come out of mgnetic field Informtion Incomplete Q. No. 15 A prticle of chrge q nd mss m enters normlly (t point P) in region of mgnetic field with speed v. It comes out normlly from Q fter time T s shown in figure. The mgnetic field B is present only in the region of rdius R nd is uniform. Initil nd finl velocities re long rdil direction nd they re perpendiculr to ech other. For this to hppen, which of the following expression (s) is/re correct mv B qr Option R T v m T qb Option None of these mv R qb Also R R m T v v qb m And T qb Q. No. 16 Two coxil solenoids 1 nd of the sme length re set so tht one is inside the

50 Option Option other. The number of turns per unit length re n 1 nd n. The currents i 1 nd i re flowing in opposite directions. The mgnetic field inside the inner coil is zero. This is possible when i. i nd n n 1 1 i 1 i nd n 1. n i 1 i nd n 1 n i1n 1 in For will 1, For coil n 1,i 1 n,i For mgnetic field to be zero n1i 1 ni n i n i 1 1 Q. No. 17 A thin wire of length is crrying constnt current. The wire is bent to form circulr coil. If rdius of the coil, thus formed, is equl to R nd number of turns in it is equl to n, then which of the following grphs represent (s) vrition of mgnetic field induction (B) t centre of the coil Option Option Conceptul

51 Q. No. 18 A prticle of mss m nd chrge q enters uniform mgnetic field B (perpendiculr to pper inwrd) t P with velocity v t n ngle nd leves the field t Q t ngle / s shown. Then must be equl to / Option Option Length PQ mvcos qb Length PQ mvsin qb Prticle remins in the field for time t m qb From figure we cn see /(properties of circle) Length PQ rcos 9 mv sin qb r m v qb Q. No. 19 A chrge prticle with velocity vxi+y j moves in mgnetic fieldby i+x j. The

52 mgnitude of mgnetic force cting on the prticle us F. Identify the correct sttements. No force will ct on prticle if x y. Option F x y if x>y The force will ct long positive z xis if x <y. Option The force will ct long negtive y xis if x >y. F qv B q xi+y j y i+x j q x k+y k q x y k Q. No. 11 An prticle is fired from origin with velocity vv j+v k in uniform mgnetic fieldb j. In the subsequent motion of prticle Its z coordinte cn never be negtive. Option Its x coordinte cn never be positive. Its x nd z co ordinte cnnot be zero t the sme time. Option Its y coordinte will be proportionl to its time of flight. F B v i Hence the motion of the prticle will be helix long negtive x xis. Q. No. 111 A chrge prticle moves in uniform mgnetic field B i j T If velocity of prticle is k m/s, the prticle moves in circulr pth Option If velocity of prticle is i+ j m/s, prticle moves in stright line. If velocity of prticle is i+ j m/s, prticle constitute helix. Option In ll the bove three cses velocity of the prticle remins unchnged. It prticle is moving in direction of k then it will be perpendiculr to mgnetic field hence it will follow in circulr pth. If velocity is in x y plne prticle will follow stright line Q. No. 11 Sttement 1:A long stright conductor crrying current lies long the xis of current crrying circulr ring. The conductor will not exert mgnetic force on the ring. Sttement : The mgnetic field due to the stright conductor lying long xis of current crrying ring coincides with the ring. Sttement 1 is True, sttement is True; sttement is correct explntion for sttement 1.

53 Option Sttement 1 is true, Sttement is True; Sttement is NOT correct explntion for Sttement 1. Sttement 1 is True; Sttement is Flse. Option Sttement 1 is Flse, Sttement is True. Conceptul Q. No. 113 Sttement 1: Two long prllel conductors crrying currents in the sme direction experience force of ttrction. Sttement : The mgnetic fields produced in the spce between them re in the opposite direction. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1. Option Sttement 1 is true, Sttement is True; Sttement is NOT correct explntion for Sttement 1. Sttement 1 is True; Sttement is Flse. Option Sttement 1 is Flse, Sttement is True. If they (Mgnetic Field) re in opposite direction then only the force will be ttrctive. Q. No. 11 Sttement 1 : The mgnetic field t the center of the circle coil in the following figure due to the current I 1 & I is zero Sttement : I 1 I in bove figure implies tht the fields due to the current I 1 & I will be blnced t center Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1. Option Sttement 1 is true, Sttement is True; Sttement is NOT correct explntion for Sttement 1. Sttement 1 is True; Sttement is Flse Option Sttement 1 is Flse, Sttement is True Correct Answer 3 The mgnetic field t the centre is dependent on current s well s ngle mde t centre. Q. No. 115 Sttement 1:A sttionry chrged prticle in stedy, non uniform mgnetic field does not experience force. Sttement : The mgnetic Lorentz force cting on the chrge prticle is directly proportionl to mgnitude of the velocity of the prticle. Option1 Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1. Option Sttement 1 is true, Sttement is True; Sttement is NOT correct explntion for Sttement 1. Sttement 1 is True; Sttement is Flse

54 Option Sttement 1 is Flse, Sttement is True F qv B Q. No. 116 Sttement 1:An electron is pssing through field nd no force cts on it. The field my be mgnetic. Sttement : On chrge mgnetic force is zero if velocity is prllel to mgnetic field. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1. Option Sttement 1 is true, Sttement is True; Sttement is NOT correct explntion for Sttement 1. Sttement 1 is True; Sttement is Flse Option Sttement 1 is Flse, Sttement is True Conceptul Q. No. 118 Sttement 1: A chrged prticle moves perpendiculr to mgnetic field. Its Kinetic energy remins constnt, but momentum chnges. Sttement : Mgnetic force cts perpendiculr to velocity of the prticle. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True Correct Answer As prticle goes in circulr pth its velocity chnges t every point. Momentum chnges. Q. No. 119 Sttement 1: Moving chrge prticle trces helicl pth in uniform mgnetic field provided xis of the helix is perpendiculr to mgnetic field. Sttement : If moving chrged prticle enters perpendiculrly into region of the mgnetic field from outside, it does not complete circulr pth. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True Correct Answer The xis is long mgnetic field Q. No. 1 Sttement 1: A chrged prticle is moving in circulr pthg with constnt speed of in uniform mgnetic field. If we increse the speed of the prticle three times its ccelertion will become nine times. Sttement : In circulr pth with constnt speed, ccelertion is given by v R. Sttement 1 is True, Sttement is True; Sttement is correct explntion for

55 Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True Correct Answer conceptul Q. No. 11 Sttement 1: Cyclotron is device which is used to ccelerte the positive ions. Sttement : Cyclotron frequency does not depend on the velocity of the chrged prticle. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True Correct Answer Both sttements re true but they ren t relted. Q. No. 1 Sttement 1: A solenoid tends to expnd, when current psses through it. Sttement : Two stright prllel metllic wires crrying current in opposite direction repel ech other. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True Correct Answer For solenoid to expnd/ compress the force should be in direction of mgnetic field which isn t possible dfidlb Q. No. 13 Sttement 1: A losselybound helix mde of stiff wire is suspended verticlly with lower end just touching dish wire executes oscilltory motion with the lower end just jumping out of nd into mercury. Sttement : When current is pssed through helix, it crries current in the sme direction nd ttrctive pull pulls the lower end out of mercury. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True conceptul Q. No. 1 Sttement 1: When chrged prticle is fired in mgnetic field the rdius of the circulr pth is directly proportionl to the kinetic energy of the prticle.

56 Option Option Correct Answer We know Sttement : The centripetl force on chrge q provided by the field will be qbv, where v is speed nd B is the mgnetic field. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Sttement 1 is Flse, Sttement is True r $ KE mv r qb mke qb Q. No. 15 Sttement 1:The poles of the mgnet cnnot be seprted by breking into two pieces. Sttement : When the mgnet moment will be reduced to hlf. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True Correct Answer The monopole doesn t exists in mgnet. ml Q. No. 16 Sttement 1: Mgnetic field t point on the surfce of long cylindricl wire is mximum. Sttement : For mny other point closed loop perpendiculr to the wire nd of rdius equl to distnce between xis of the wire nd given point will enclose less current. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True Correct Answer 3 The mgnetic field B$ r Q. No. 17 Sttement 1: A chrged prticle is projected into region of mgnetic prticle will remin constnt. Sttement : Work done by the mgnetic field on the chrged prticle will be zero. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True

57 In circulr motion the speed remins constnt. Q. No. 18 Sttement 1: A liner solenoid crrying current is equivlent to br mgnet. Sttement : The mgnetic lines of both re identicl. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True Conceptul Q. No. 19 Sttement 1: A proton moving verticlly upwrds verticlly upwrds enters mgnetic field directed towrds South. It will be deflected towrds est. Sttement : Direction of force cn be determined by Fleming s left hnd rule. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True The direction of force is determined by right hnd rule. Q. No. 13 Sttement 1: The mgnetic field t the ends of very long solenoid crrying current is hlf of tht t the centre deep inside the solenoid. Sttement : If the solenoid is sufficient long the field within it is uniform. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True Correct Answer Conceptul Q. No. 131 Sttement 1: A mgnetic field intercts with moving chrge nd not with sttionry chrge. Sttement : A moving chrge produces mgnetic field round it. Sttement 1 is True, Sttement is True; Sttement is correct explntion for Sttement 1 Option Sttement 1 is True, Sttement is True; Sttement is NOT correct explntion for Sttement 1 Sttement 1 is True, Sttement is Flse Option Sttement 1 is Flse, Sttement is True Conceptul

58 Pssge Text Two long prllel wires, distnce 6 cm prt, crrying equl current I A in opposite direction. Q. No. 13 The mgnetic field t point midwy between the wires is 1.3T Option 1.5T 1.83T Option.3T B I T Q. No. 13 Select the correct mgnetic field versus distnce grph. The distnce x is the distnce of point, lying in the plne of the wires, from line which is the middle of the wires prllel to nd coplnr with the wires Option

59 Option Correct Answer 3 B$ 1 x Pssge Text Two long stright line thin prllel wires crry current.5 mpere nd I mpere in the sme direction (into the plne of the pper).these wires re held t P nd Q positions respectively such tht they t re perpendiculr to the plne of the pper. The point P nd Q re locted t perpendiculr distnce of 5m nd m from colliner point R.An electron moving with velocity of 1 5 m/slong positive x xis direction experiences force of mgnitude 3. 1 Nt the point R. Q. No. 135 Wht is the mgnitude of the mgnetic field t the point R..5 1 T Option Option T 5 1 T T Correct Answer We know Fq v B qvbsin hence FqVB As v* B B 7 B51 T Q. No. 136 Wht is the unknown current I in wire Q. A Option 3A A Option 5A Correct Answer 3 I1 I B + b I1 I + b

60 7 7.5 I I IA Q. No. 137 The mgnitude of the mgnetic field t point R due to current of.5 A in wire P is 1 7 T Option T 7 1 T Option T Correct Answer 7 I B 1 1 T c 5 Pssge Text Consider the rrngement shown in the figure. The loop crries the current I. Q. No. 138 Totl mgnetic field t point O due to wire 1 nd is I Option Option I I I I B sin +sin 1

61 I B 1 sin5+ sin I 1 I 1 B 6 B B 5 I B 3 B sin5+sin I 1 I 1 I 1 B Net. I 1 8 I 71 1,6 3, Q. No. 139 Totl mgnetic field due to wire 3 t the point O is Option Option Pssge Text Curves in the prgrph given, s function of rdil distnce r, the mgnitude B of the mgnetic field inside nd outside four long wires, b, c nd d, crrying currents tht re uniformly disturbed cross the cross sections of the wires. Overlpping portions of the plots re indicted by double lbels. Q. No. 11 Which wire hs the gretest rdius Option b

62 c Option d Correct Answer 3 B$ rconceptul Q. No. 1 Which wire hs the gretest mgnitude of the mgnetic field of the surfce Option b c Option d Conceptul Q. No. 13 The current density in wires is greter thn in wire c Option Less thn in wire c equl to tht in wire c Option not comprble to tht of in wire c due to lck of informtion Conceptul Pssge Text A prticle hving chrge q nd mss m is projected from origin with velocity vv i B 3B in uniform mgnetic field B i+ j Q. No. 17 Pitch of the helicl pth described by the prticle is mv qb Option Option Correct Answer mv qb 5 mv qb 6mv qb The velocity nd mgnetic field vector is mking ngle of 6 o 6 Pitch Vcos t

63 r mvsin t vsin qbv sin rv 1 mv qb qb Q. No. 19 Mximum z coordinte of the prticle is 3v Option B q 3mv B q mv B q Option mv B q The mximum z coordinte will be sme s rdius only mvsin6 r Bq 3mv B q key correction Pssge Text A rigid circulr loop hs rdius of. m nd is in the x y plne. A clockwise current I is crried by the loop, s shown the mgnitude of the mgnetic moment of the loop is.75 A m. A uniform externl mgnetic field, B. T in the positive x direction, is present Q. No. 15 In figure, the mgnitude of the mgnetic torque exerted on the loop is closest to.55 N m Option.15 N m.5 N m Option.35 N m Correct Answer Torque B N m Q. No. 151 In figure the loop is relesed from rest. The initil motion of the loop is described by Point moves out of the plne, point c moves into the plne Option Point, b, c nd d move counterclockwise Point, b, c nd d move clockwise Option Point c moves out of the plne, point moves into the plne Conceptul

64 Pssge Text Any object of finite size contins lrge number of toms. The mgnetic moments of these toms re rndomly oriented nd there is no net mgnetic moment in ny volume of the mteril tht contins more thn severl thousnd toms (figure ). However, when the mteril is kept in n externl mgnetic field, torques ct on the tomic dipoles nd these torques try lign them prllel to the field (figure b). The lignment is only prtil, becuse, the therml motion of the toms frequently chnges the orienttion of the toms nd hence tries to rndomize the mgnetic moments. The degree of lignment increses if the strength of the pplied field is incresed nd lso if the temperture is decresed. With sufficiently strong fields, the lignment is ner perfect. When the tomic dipoles re ligned, prtilly or fully, there is net mgnetic moment in the direction of the field in ny smll volume of the mteril. We define the mgnetiztion vector I s the mgnetic moment per unit of volume. It is lso clled the intensity of mgnetiztion. With this informtion, nswer the question on mgnetic mterils. Q. No. 153 The number of toms per unit volume in smple of iron is 91 8 toms / m 3. The mgnetic moment of every iron tom is A.m if ll the dipoles re ligned in domin due ferromgnetic interction then the mgnetiztion of iron rod of length 1 cm nd re of cross section 1 cm will iron rod of length 1 cm nd re of cross 1 cm will be A/m Option A/m A/m Option A/m Option 5 Option 6 Q. No. 158 A negtive chrged prticle of mss m hving chrge q enters in mgnetic field B B k t point P (3m,, ) with velocity v 3 j + k t t s shown in the figure m [ Given 1 ] [ No other field is present ] B q

65 Column I Pitch of the motion of prticle rdius of curvture of prticle 5 during motion t time t t sec. Velocity component of prticle in xy plne Accelertion of prticle A R, B S, C P, D Q Option A Q, B R, C S, D P A S, B Q,C P, D R Option A P, B S, C R, D Q Column II ( 3sint i +3cost j) unit ( 3cost i 3sint j) unit 8 unit Constnt B B k v 3 j + k Velocity long field V k V j 3 p Vk t 3.m 8 Bq A R B S constnt conceptul Q. No. 159 A squre current crrying loop is plced in x y plne, uniform mgnetic field B Bk Is present in the region. Mtch the column I with column II Column I Column I Mgnetic moment of the loop Zero Torque on the loop Minimum Potentil energy of the loop Stble Equilibrium of the loop Along z xis A S, B P, C Q, D R Option A R, B Q, C P, D S

66 A Q, B S, C R, D P Option A S, B R, C Q, D P Mgnetic moment I A ) B P.E..B A) S B) P C) Q D) R Q. No. 16 Column II gives force expression for current crrying wire shown in Column I. Mtch them correctly. Column I Column I BiR Zero BiR BiR A Q, B P, C Q, D P Option A P, B Q, C P, D Q A Q, B P, C Q, D P Option A P, B Q, C Q, D P A) Q conceptul B) P conceptul C) Q Due to symmetry we cn see tht the net force is zero D) P) F ilb i R B BiR Q. No. 161 Two long prllel wires crrying equl currents in opposite directions re plced t x prllel to y xis with z then mtch correctly column 1 with column Column I Column II Mgnetic field B 1 t origin (,, ) I

67 Mgnetic field B t origin (,, ) Mgnetic field B 3 t origin (,, ) Mgnetic field B t origin (,, ) A P, B R, C R, D Q Option A Q, B R, C P,Q;, D R A R, B P,Q; C P, D R Option A R, B R, C P,Q; D Q I I 3 I At the origin the field will dd up B i R At (,, ) I I B Net 6 I 3 At B3 9,, I I B. B 9,, I I B. Q. No. 16 Regrding the trjectory of chrged prticle, when prticle experiences Lorentz force, mtch following correctly from column 1 with column Column I Column II In Electric field only Helicl pth In mgnetic field only Stright line pth In mutully perpendiculr fields, chrge Circulr pth t rest In cross fields Cycloidl pth Prbolic pth A Q.T; B P,Q,R; C S. D Q Option A Q, B S, C P,Q,R; D Q,T A P,Q,R; B Q, C Q,T; D S Option A Q,T; B S, C Q,T; D P,Q,R A) Q,T

68 B) P,Q, R C) S D) Q conceptul Q. No. 163 A wire PQ of mss 1g is t rest on two prllel metl rils. The seprtions between the rils re.9 cm A mgnetic field of.8 Tesl is pplied perpendiculr to the plne of the rils. The resistnce of the circuit is slowly decresed. When the resistnce decresed to below, the wire PQ begins to slide on the rils. Clculte the coefficient of friction between the wire nd the rils [in 1 ] Is Integer Type For rils to move ilb mg vlb Rmg Q. No. 16 A copper wire hving resistnce of.1 ohm in ech meter is used to wind turn solenoid of rdius 1 cm nd length of cm Wht is the e.m.f?, volt of the idel bttery which when connected cross the solenoid will cuse mgnetic field of 1 tels ner the centre of the solenoid. Is Integer Type Mgnetic field in solenoid is given by

69 7 B ni 1 i 1 B ni 7 v v 1v Q. No. 165 Wht is mgnitude of mgnetic field (B 1 6 T) t O of the reference frme if the wire crrying current i 1 A hs the liner shpe shown The rdius of curve prt is R 1cm The liner prt of wire re very long. Correct Answer 3 Is Integer Type Due to wire long x xis mgnetic field is i B x k Due to loop B l i 8r Due to wire long y xis i B y i i B Q. No. 166 A prticle of mss kg nd chrge C trvelling with velocity of Correct Answer 6 Is Integer Type m/s in the positive x direction enters region in which uniform electric field E nd uniform mgnetic field of induction B re present such tht 6 E x E y, E z 1.5 KV/m nd B x B z, B y 8 1 T The prticle enters this region t t. Determine the loction of the prticle t t 5s.