Magnetic Field due to current Questions and Answers

The direction of force on the charge q moving in uniform magnetic field as shown in following figure is towards X X X X 9 v X X X X X X B C ve x direction ve y direction ve y direction

Only circular part of the wire shown in the figure has resistance per unit length The radii of the circles are r and R and ZPOQ a in radian potential difference V V V is applied across the point P and Q the magnetic field point O is O O O V 27 a a R 4mg Q Ho a 27 a 4 R Ho Gr

An infinite V shaped wire carrying current I is shown in the adjacent figure Find the magnitude of magnetic field at point P due to the wire if AP r A C Hol 2 r Hol 2 r tan 0 cot 0 G 2 I B tan 2 r D zero 0 A pr Le 8

The peak value of an alternating e m f E E sin oot is 10 volt and its frequency is 50 Hz At a time t the e m f is 1 1 volt 3 5 volt 1 600 s the instantaneous value of 2 5 3 volt 4 10 volt

Figure shows a long straight wire carrying current I and a square conducting wire loop of side 1 at a distance a from current wire Both the current wire and loop are in the plane of paper Find the flux of magnetic field of current wire passing through the loop 8 14 a X o unengmoo Aben xxxxxxx dx b 8

40 An ionized gas contains both positive and negative ions If it is subjected simultane ously to an electric field along the x direction and a magnetic field along the z direction then 1 positive ions deflect towards y direction and negative ions towards y direction 2 all ions deflect towards y direction 3 all ions deflect towards y direction 4 positive ions deflect towards y direction and negative ions towards y direction 4 e

Q10 Eddy currents are produced in a conductor when the conductor is subjected to Ospecific value of magnetic field Ono magnetic field varying magnetic field O constant magnetic field Clear selection

A conducting movable rod AB lies across the frictionless parallel conducting rails in a uniform magnetic field B whose magnitude at t 0 is B The rod AB is given velocity v right ward and it continues to move with same velocity through out the motion f b The acceleration due to gravity is along negative z axis i e g 10m s k mass of rod m Which of the following graphs will be the best representation of magnitude of magnetic field versus time A B C Bo B Bo B D ww B Bo B Bo

Two long parallel wires are at a distance of 1 metre Both of them carry one ampere of current The force of attraction per unit length between the two wires is 1998 5 x 10 8 N m 2 x 10 8 N m 2 x 10 7 N m 10 7 N m

A cylindrical conductor of radius R is carrying a constant current The plot of the magnitude of the magnetic field B with the distance d from the centre of the conductor is correctly represented by the figure NEET 2019 B B R d R d

A square loop carrying a steady current I is placed in a horizontal plane near a long straight conductor carrying a steady current at a distance d from the conductor as shown in figure The loop will experience 1 d I Mains 2011 a net attractive force towards the conductor a net repulsive force away from the conductor

Two parallel wires in free space are 10 cm apart and each carries a current of 10 A in the same direction The force exerted by one wire on the other per metre length is 1997 2 x 10 4 N repulsive 2 x 10 7N repulsive 2 x 10 4 N attractive 2 x 10 7N attractive

10 Two short magnets of equal dipole moments M are fastened perpendicularly at their centres as shown below point P is in the plane of the magnets D 1 Ho M 4 da The magnetic field magnitude at P distance d from the centre on the bisector of the right angle is S n Ho2M 2 S Ho M 2 An N N Ho 2 2M que

A thin rectangular magnet suspended freely has a period of oscillation equal to T Now it is broken into two equal halves each having half of the original length and one piece is made to oscillate freely in the same field If its period of oscillation is T the ratio T T is A B skipped 1 2 2 2 2

210 A small magnetic needle is kept at 0 0 with its moment along the x axis Another small magnetic needle is at the point 1 1 and is free to rotate in the xy plane Show where angle is the angle between their magnetic that in the equilibrium sin moments 3 10

Moving Charges and Magnetism Magnetism and Matter A positively charged particle of charge q travelling along positive x axis initially enters in a uniform magnetic field B directed inward and is deflected a distance y after travelling a distance x as shown in the figure Then the magnitude of linear momentum of the particle is A C X X X X X X X X Ou qBxo 2 X X X X X X X X X X XXX X X X X X X X X X X XXXXXX qB 1 x y X X X XX X x xx xx XXX X XX X X X B D qB 2 Yo qB X Ou Xo x y

Q 40 Magnetic field due to 0 1 A current flowing through a circular coil of radius 0 1 m and 1000 turns at the centre of the coil is 1999 6 28 10 4 T 4 31 x 10 T 00 0 2 x 10 T

A straight conductor carrying current i splits into two parts as shown in the figure The radius of the circular loop is R The total magnetic field at the centre P at the loop is 90 R Zero P Odisha NEET 2019 3 oi 32R outward

Two similar coils of radius R are lying concentrically with their planes at right angles to each other The currents flowing in them are and 21 respectively The resultant magnetic field induction at the centre will be 2012 5 1 2R 5 01 R

A proton and an alpha particle both enter a region of uniform magnetic field B moving at right angles to the field B If the radius of circular orbits for both the particles is equal and the kinetic energy acquired by proton is 1 MeV the energy acquired by the alpha particle will be 2015 1 5 MeV 1 MeV 4 MeV 0 5 MeV

51 A semicircular loop of radius R is located on the boundary of a uniform magnetic field B The loop is set into rotation with a constant angular acceleration a about an axis O at t 0 Which of the following graph is between emf induced vs time 1 g X X X X B X X X X X X 2 4 E K E

4 Both 1 2 2 Two magnets are held together in a vibration magnetometer and are allowed to oscillate in the earth s magnetic field With like poles of magnets together 12 oscillations per minute are made but for unlike poles together only 4 oscillations per minute are executed The ratio of their magnetic moments is 1 3 1 3 3 5 2 1 3 4 5 4 32 4 1 un to 2 chan T 1 3 1 3 3 5 eat gr faatfeefa 12 te auf 2 1 3 4 5 4

A uniform magnetic field acts right angles to the direction of motion of electrons As a result the electron moves in a circular path of radius 2 cm If the speed of electrons is doubled then the radius of the circular path will be 1991 2 0 cm 0 5 cm 4 0 cm 1 0 cm

A charged particle moves through a magnetic field in a direction perpendicular to it Then the 2003 speed of the particle remains unchanged direction of the particle remains unchanged acceleration remains unchanged velocity remains unchanged

A straight wire of length 0 5 metre and carrying a current of 1 2 ampere is placed in uniform magnetic field of induction 2 tesla The magnetic field is perpendicular to the length of the wire The force on the wire is 1992 2 4 N 1 2 N 3 0 N

A single straight wire produces a B field Another wire is parallel and carries an identical current If the two currents are in the same direction how would the magnetic field be affected What if the currents are in the opposite direction

Asseetion A When a magnetic dipole is placed in a non uniform magnetic field only a torque acts on the dipole Reason R Force would act on dipole if magnetic field is uniform A a B b C c D d

Consider the following two statements about the Orested s experiment Statement P The magnetic field due to a straight current carrying conductor is in the form of circular loops around it Statement Q The magnetic field due to a current carrying conductor is weak at near points from the conductor compared to the far points A Both P and Q are true B Both P and Q are false C P is true but Q is false D P is false but Q is true

A metallic rod of mass per unit length 0 5 kg m is lying horizontally on a smooth inclined plane which makes an angle of 30 with the horizontal The rod is not allowed to slide down by flowing a current through it when a magnetic field of induction 0 25 T is acting on it in the vertical direction The current flowing in the rod to keep it stationary is NEET 2018 7 14 A

A rod ABC shown in the figure is made up of two parts The part AB is non conducting while the part BC is conducting The rod rotates with constant angular speed w about an axis perpendicular to its length and passing through the end A The axis carries a constant current I The emf iduced across the ends A and Cis A G B C

f the magnetic field of a plane electromagnetic wave is given by The speed of light 3x10 m s 8 100x10 sin 2xx2x10 s 1 1 then the maximum electric field associated with it is O 6 x 10 N C O 3 x 10 N C O 4 5 x 10 N C 4 x 104 N C

SolveLancer Test A student was doing some experiment related to magnetism He found that the magnetic flux linked with a coil varies as B 13t 7t 2t 8 Wb The magnitude of the emf induced at t 1 s is SolveLancer Test a b c d 39 V 55 V 63 V 53 V

Find the current through Ro when the rod rotates through an angle 0 The rod AD is pushed with initial angular velocity wo at the position AC on a semicircular conductor about A in a uniform magnetic field perpendicular to the plane of semicircular loop The length of the rod is r and resistance R the rod rotates in a horizontal plane Ignore the resistance of semicircular conductor CH 00p A OR D 3 OB Ro

A charged particle electron or proton is introduced at the origin x 0 y 0 z 0 with a given initial velocity y A uniform electric field and a uniform magnetic field exist everywhere The velocity v electric field and magnetic field Bare given in columns 1 2 and 3 respectively The quantities Eo Bo are positive in magnitude Column 1 1 Electron with V 2X 11 Electron with v i E E B E Ei N E E X III Proton with 0 Column 2 2 x E E IV Proton with 2x 2x II ii R III iii P V i S Read Less Column 3 In which case will the particle describe a helical path with axis along the positive z direction P B 8 Q B B x R B Boy S 8 8 2

Question 1 A washer is made of metal having resistivity 10 7 m The washer has inner adius 1 cm outer radius 3 cm and thickness 1 mm A magnetic field oriented normal to the lane of the washer has the time dependent magnitude B 2t tesla sec Find the current in mpere around the washer Options a 2 amp b 4 amp c 6 amp JO

4 40 x 10 6 T A long wire with a small current element of length 1 cm is 5 Tandanam placed at the origin and carries a current of 10A along x axis Find out the magnitude of magnetic field due to the element on the y axis at a distance 0 5 m from it 1 2 x 10 T 2 2 10T 3 4 x 10 BT 4 4 x 10 6T 4 40 x 10 T 10 fax referencan 1 2 x 10 T 3 4 x 10 BT 0 5 far 2 2 x 10 T 4 4 x 10 T

A proton is moving along x axis as shown in the figure The direction of induced current in the loop is Proton V Closed loop 1 First anti clockwise then clockwise 2 First clockwise then anticlockwise 3 Anticlockwise always 4 Clockwise always X

55 A closed circular conducting loop is mo a uniform magnetic field as shown in the figure Select correct statements X X X B X X V X OF X X 1 Induced emf in closed loop is zero but between points P and Q it is not zero 2 Induced emf in closed loop is non zero but between points P and Q it is zero 3 Induced emf in closed loop as well as between points P and Q are zero 4 Induced emf in closed loop as well as between points P and Q are non zern 59

4 28 A beam of non relativistic charged particles moves without deviation through the region of space A where there are transverse mutually perpendicular electric and magnetic fields with strength E and induction B When the magnetic field is switched off the trace of the beam on the screen S shifts by Ax Knowing the distance a and b find the specific charge q m of the particles Ans 2mEAx

A particle of mass m and charge q is dropped from a height h In whole space there exists a constant magnetic field B as shown in figure Find the minimum value of B such that the particle just grazes the ground h m q O C B m 2q 2m 9 al m col h h 100l

Q 62 A tightly wound solenoid of length and cross sectional area A is partly inserted co axially into another tightly wound solenoid of length and cross section l A A The centres of the two solenoids are separated by x Assume that A x A 1 Calculate the total magnetic field energy inside the solenoid when both of them carry same current I in the same sense Number of turns in each solenoid is N

4 Magnetic length of bar magnet of 70 cm length is Question Type Single Correct Type 1 70 cm 2 35 cm English 3 63 cm 4 7 cm Review Q

Answer A B C D Your Attempt B dl along x axis is B di along x axis is B di along x axis is Correct answer B di along x axis is 2 Hol 12 4 OP 0 a A a 0 di X B a 3 0 Rate this quest

Shown in the figure is a circular loop of radius r and resistance R A variable magnetic field of induction B Boet is established inside the coil If the key K is closed the electrical power developed right after closing the switch is equal to 1 B R xxx R 103 BX X X X XX Question Type Single Correct Type R

A charge particle of charge q mass m is accelerated through a potential diff V volts It enters a region of orthogonal magnetic field B Then radius of its circular path will be Question Type Single Correct Type 1 2 3 Vm 2qB 2Vm qB 2Vm la

38 A magnet is made to oscillate with a particular DAT frequency through a coil as shown in figure The time variation of magnitude of emf generated across the coil during half cycle is Tan

If current I passes through a square shaped conduct ing loop of side a what is the value of the magnetic field at the point of intersection of its two diagonals

Two insulated rings one of slightly smaller diameter than the other are suspended along their common diameter as shown Initially the planes of the rings are mutually perpendicular When a steady current is set up in each of them Z Dax X The two rings rotate into a common plane The inner ring stays stationary while the outer one moves into the plane of the inner ring

A circular loop of radius a centered at origin and lying in the xy plane carries current I as shown in the figure The magnetic field intensity a the centre of the loop wi 1 4a az 1 4a az 1 2a az 1 2a az I X

Two point charges q and 2 are placed along x axis at some separation one of the electric field line emanating fro 6x charge q is along the curve as indicated in diagram If x then find the value of 1 3 80 9 92 q