Magnetic Field due to current Questions and Answers

Difference between Biot Savart and Ampere s Law

e 1 magnetic force on a proton to the right to the left upward downward into the page out of the page magnetic force on an electron to the right to the left upward downward O into the page 4 out of the page magnetic force on a proton O to the right to the left upward downward into the page O out of the page magnetic force on an electron to the right to the left ward downward into the page out of the page magnetic force on a proton to the right to the left upward downward into the page 100

d e 100 magnetic force on a proton to the right to the left upward downward into the page O out of the page magnetic force on an electron to the right to the left upward Odownward into the page O out of the page Bom magnetic force on a proton to the right O to the left O upward downward into the page O out of the page magnetic force on an electron O to the right to the left upward downward O into the page out of the page magnetic force on a proton O to the right Oto the left upwart downward

Can a charged particle move through a magnetic field without experiencing any force If so how If not why not At any point in space the electric field E is defined to be in the direction of the electric force on a positively charged particle at that point Why don t we similarly define the magnetic field B to be in the direction of the magnetic force on a moving positively charged particle The magnetic force on a moving charged particle is always perpendicular to the magnetic field B Is the trajectory of a moving charged particle always perpendicular to the magnetic field lines Explain your reasoning

Consider an infinitely long solenoid with N turns per unit length radius R and carrying current 1 t a cos wt where a is a constant and wo is the angular frequency The magnitude of electric field at the surface of the solenoid is A HONRwa sin wt C ONRwa sin wt B HowNR cos wit D HowNR cos wt

A negative charge is given to a non conducting loop and the loop is rotated in the plane of paper about its centre as shown in the figure The magnetic field produced by the ring affects a small magnet placed above the ring in the same plane such that S N 1 the magnet does not rotate 2 the magnet rotates clockwise as seen from below 3 the magnet rotates anticlockwise as seen from below

A wire of length 500m at a height of 20m above the surface of earth is carrying a current of 50A The current is flowing in the south north detection Earth s magnetic field is at an angle of 600 with the vertical and its strength is x 10 4Weber meter2 Given Ho 4 10 7N Find the magnitude and direction of the force experienced by the wire

A rectangular loop of sides 6 cm and 2 cm with a small cut is moving out of a region of uniform magnetic field of magnitude 0 4 T directed normally to loop The voltage developed across the cut if velocity of loop is 2 cm s 1 in the direction normal to longer side is 1 3 8 x 10 4 V 2 4 8 x 10 V 3 2 4 x 10 V 4 6 2 x 10 V Tam t D 20m

3 2 0 In figure there are two concentric coils in perpendicular planes carrying equal currents Magnetic field at centre is B If current in one coil becomes zero then magnitude of new magnetic field will be 1 B2 B 3 F 2 B 3 4 B 2

A metallic pendulum if oscillating in a uniform magnetic field directed perpendicular to th plane of Oscillation then it will a slow down c remain unaffected b d become faster oscillates with a changing frequency

A B C D A B Column I Magnetic field lines Magnetic field lines within the magnet Magnetic field lines outside the magnet Magnetic field inside a tightly wound long solenoid D A P B Q C R D S AS BR C Q D P C AP BQ C S DR AQ B R CS D P P Q R S Column II Uniform Closed curves South pole to the north pole North pole to the South pole

A loop of irregular shape of conducting wire PQRS as shown in figure placed in a uniform magnetic field perpendicular to the plane of the paper changes into a circular shape The direction of induced current will be A Clockwise C No current x x x x B Anti clockwise D Name of these

A semicircular wire of radius r carrying current 1 is placed in a magnetic field of magnitude B The force acting on it 1 Can never be zero 2 Can have maximum magnitude 2Blr 3 Can have the maximum magnitude Blan magnitude Bir

22 A circular loop of radius R is kept in a uniform magnetic field pointing perpendicular to plane of figure when the current I flows in loop the tension produced in the loop is 1 BIR BIR 2 3 2BIR 2 X X X X X4 X X X X X X X X X X x Rx X X X X X X X X X That

19 If the electric field and if magnetic field are mutually perpendicular to each other then a charged particle would move undeflected if 1 v E B 2 v B E 3 v BE 4 v B E 1 Here charge particle is moving perpendicular to d a c both E and B

Q23 The force between two parallel wire A and B carrying current is 0 004N m The conductors are 0 01m apart If the current in conductor Ais twice that of conductor B then the current in the conductor B would be O 5A 50A 10A 100A

A very long straight wire carries a current 1 At instant when a charge Q at point P has velocity v as shown the magnetic force on the charge is 1 along ox 2 opposite to oy 3 along oy to 1 P x

A long straight conductor is carrying a current of 20 A as shown in the figure At a distance of 5 cm from it a square loop PQRS of side 15 cm is placed with its side PQ nearest to the wire If the square loop carries a current of 10 A as shown what is the net force on the loop 20 AT Q 10 A 5 cm 4 15 cm 9 x 10 5 N Attractive 4 5 x 10 4 Attractive 15 cm R

Two metal strips each of length 1 are clamped parallel to each other on a horizontal floor with a separation b between them A wire of mass m lies on them perpendicularly as shown in figure 34 E8 A vertically upward magnetic field of strength B exists in the space The metal strips are smooth but the coefficient of friction between the wire and the floor is u A current i is established when the switch S is closed at the instant 0 Discuss the motion of the wire after the switch is closed How far away from the strips will the wire reach S

20 Two electrons are forced to more in opposite direction on two parallel lines separated by 2m Find electric force between them where separation between them is minimum 2 m K v 4 m s a 5 76 10 10 N b 5 76 10 29 N c 10 52x10 34 N d zero 1 In above Q 20 when these separation is minimum Find magnetic force between them a 2 56 10 45 N 10 45 N b 5 12x10 50 N d Zero

2 5 In a factory boxes are circulated in a moving belt which is inclined as shown in figure The belt is rotating at 625 constant speed A particular box has a radius of 8 cm The coefficient of static friction between box and belt is 0 8 The belt is inclined at 37 The time required by box to go around once Assuming limiting friction Take n g A 5 sec B 10 sec 37 C 15 sec D 20 sec

If the magnetic field is denoted by the right hand fore finger and the induced current denoted by the middle finger the thumb finger denotes the direction of motion of the conductor If the magnetic field is opposite to the direction of the length of the wire the current induced will be Zero Non zero to magnetic field

A conducting rod shown in figure rotates about point Cas pivot with constant frequency of 5 rev s What is potential difference across its ends 80 cm apart due to magnetic field of 0 3 T conducting rod X 3 V O 02V O 8V b

A ring of radius R and charge Q is place d as shown attached image if a charg e q of mass m is initially at point A the n find its velocity when it reaches to poi nt B Please solve this question by integrati on method as I know the mechanical energy approach already t KRI BR m 90 A J R

A rocket zooms past the earth at v 2 0 x 10 m s Scientists on the rocket have created the electric and magnetic fields shown in the figure Figure 1 Assume that B 0 50 T and E 5 0 105 V m B What is the magnetic field strength measured by an earthbound scientist Express your answer using two significant figures VAE Part A What is the electric field strength measured by an earthbound scientist Express your answer using two significant figures VAX Submit My Answers Give Up B T V m

A uniform charged rod of specific charge a is placed within a ideal solenoid with direction perpendicular to axis of solenoid Mid point of rod is at center of solenoid Due to current in solenoid an uniform magnetic field Bi within it Suddenly current in solenoid is switched off then Rod will start motion along the axis of solenoid aB 2 Rod will perform rotation about its centre with angular velocity aB Rod will perform rotation about its center with angular velocity Motion of rod will be in plane perpendicular to axis to solenoid

A wire of length 4 cm is placed inside t he solenoid near the centre at certain a ngle with the axis of the solenoid The w ire carries a current of 10 A experience a force of 0 004 N in the magnetic field 2 5 10 2T due to the solenoid What i s the angle made by the wire with the a xis of the solenoid

Current lo flows through the solenoid of length L havin g N number of turns when its connected to DC A charged particle is projected perpendicular to magnetic field of the solenoid with a speed v0 then the force on the charged p article in the solenoid

A long straight wire of radius r carries a current i and is placed horizontally in a uniform magnetic field B pointing vertically upward The current is uniformly distributed over its cross section a At what points will the resultant magnetic field have maximum magnitude What will be the maximum magnitude b What will be the minimum magnitude of the resultant magnetic field

A long straight wire carrying current I and a rectangular frame with side lengths a and blie in the same plane as shown in the figure The mutual inductance of the wire and frame is Options 1 Ho 2 ab I

A thin diamagnetic rod is placed vertically between the poles of an electromagnet When the current in the electromagnet is switched on then the diamagnetic rod is pushed up out of the horizontal magnetic field Hence the rod gains gravitational potential energy The work required to do this comes from NEET 2018 1 The current source 2 The magnetic field 3 The induced electric field due to the changing magnetic field 4 The lattice structure of the material of the rod

23 A circular ring of radius r is placed in a homogeneous magnetic field perpendicular to the plane of the ring The field B changes with time according to the equation B Kt where K is a constant and is the time The electric field in the ring is Kr Find the value of P P If 10000 Y is applied across an X ray tube what will be

4 A vertical circular coil of radius 0 1 m and of 10 turns car ries a steady current When the plane of the coil is normal to the magnetic meridian a neutral point is observed at the centre of the coil If B 0 314 10 4T what is the mag nitude of the current flowing through the coil

2 29 There is a constant homogeneous electric field of 100 Vm within the region x 0 and x 0 167 m pointing in the positive x direction There is a constant homogeneous magnetic field B within the regionx 0 167 m and x 0 334 m pointing in the z direction A proton at rest at the origin x 0 y 0 1910 is released in the positive x direction The minimum strength of the magnetic field B so that the proton will come back at x 0 y 0 167 m mass of the proton

A non conducting rod of length 15 cm and linear charge density 100 C m is hinged at one end It is kept in horizontal position in vertical plane in front of a current carrying wire carrying current 100 A as shown in figure The system is released from horizontal position Find the magnetic force in mN on the rod at that instant when it makes angle 60 with the downward vertical 15 cm a 2 100 C mAh 93 h yg At uz Hafha P 1 3 fa tef cu 100 A ngu fy y ych was az M47 G fuz da zu ga 1 Acu c Au Ka 35 EUR Affa 42 Afg 60 M 1 1

A charge of 8 84 C is traveling at a speed of 6 02 x 106 m s in a region of space where there is a magnetic field The angle between the velocity of the charge and the field is 55 1 A force of magnitude6 02 10 3 N acts on the charge What is the magnitude of the magnetic field

A solid cylindrical conductor of radius R has a uniform current density The magnetic field H inside the conductor at a distance r from the axis of the conductor is I 2 r a TN b I 4 Tr c fr 2 R d Ir 4 R

A uniform magnetic field B exists perpendicular to the plane of figure in a circular region of radius b as shown A circular conductor of radius a b and centre at O is made of joining two semi circular wires ABC and ADC The two segments have same cross sections but different resistances R and R respectively The magnetic field is increased with time and there is an induced current in the conductor R R x XCXX Choose the current statement s E R E R A The ratio of electric fields inside conductors ABC and ADC is C The ratio of electric fields inside conductors ABC and ADC is En The net accumulated charge is positive at junction C R R

Two long wires one carrying current 1 A and other carrying 2 A in the same direction are placed parallel to each other produces a net magnetic field B at the mid point What will be the field at mid point when current 1 A is switched off NCERT Pg 148 1 B 2 2B 3 B 2 3B

Correct Questions 27 180 Same current is flowing in three infinitely long thin wire along positive x y and z direction The magnetic field at a point 0 0 a would be 2 a H i i Hol 2na Ho i k

2 What is peak electric field produced by the radiations coming from 100 W bulb at a distance 3 m Assuming that bulb is poin source with efficiency of 2 5 1 2 9 V m 3 1 6 V m NCERT Pg 279 2 3 1 V m 4 4 07 V m

One of the two small circular coils none of them having any self inductance is suspended with a V shaped copper wire with plane horizontal The other coil is placed just below the first one with plane horizontal Both the coils are connected in series with a dc supply The coils are found to attract each other with a force Which one of the following statements is incorrect A both the coils carry currents in the same direction 2013 B Coils will attract each other even if the supply is an ac source C Force is proportional to d d distance between the centers of the coils D Force is proportional to d

Two circular coils mounted parallel to each other on the same axis carry steady currents If an observer betwe the coils reports that one coil carrying a clockwise current i while other is carrying a counter clockwise curre i between the two coils then there is 1 Steady repulsive force 3 A repulsive force A long straight 2 Zero force 4 A steady attractive force

xi In figure 5 54 a wire ring of radius R is in pure rolling on a surface Find the EMF induced across the top and bottom points of the ring at any instant X X X R Figure 554 X

current i are equally placed as shown in the figure Adjacent wires have current in opposite direction Net magnetic field at point P is 45 a 2 x N

5 A current I flows in an infinitely long wire with cross section in the form of a semi circular ring of radius R The magnitude of the magnetic induction along its axis is a Ho 2n P c Ho Hol 2 R c Hol b

In the figure given below a current carrying infinitely long wire is shown Find the magnitude of magnetic field at point P 1 2 3 Mo 3 1 2 2 3 1 Mo 3 1 4 30 30 P 90 a

4 17 A current i 5 0 amp flows along a thin wire shaped as shown in figure 4 253 The radius of a curved part of the wire is equal to R 120 mm the angle 20 90 Find the magnetic induction of the field at the point O A 20 90 R Figure 4 253 B

Consider the possibility of a new design for an electric train The engine is driven by the force due to the vertical component of the earths magnetic field on a conducting axle Current is passed down one coil into a conducting wheel through the axle through another conducting wheel then back to the source via the other rail i What current is needed to provide a modest 10 KN force Take the vertical component of theearth s field be 10 T the length of axle to be 3 0 m ii How much power would be lost for each of resistivity in the rails iii Is such a train unrealistic

in a An electric current runs counterclockwise rectangular loop around the outside edge of the page which lies flat on your table A uniform magnetic field is then turned on directed parallel to the page from top to bottom The magnetic force on the page will cause 1 The left edge to lift up 2 The right edge of lift up 3 The top edge to lift up 4 The bottom edge to lift up