Magnetic Field due to current Questions and Answers

A cell is connected between the points A and Cof a circular conductor ABCD of same material with centre at O If B and B are the magnitude of magnetic field at O due to current in ABC and ADC respectively then ratio is B B B 05 6 O 2 60 D YC

128168 current carrying As shown in diagram a conductor is subjected to steady uniform magnetic field Then B Torque t 0 force F 0 Torquet 0 force F 0 Torque T 0 force F 0 Torque T 0 force F 0

A charged particle of mass m enters a region of uniform magnetic field B with velocity making an angle of 30 with the direction of the magnetic field The path of such a particle is

Two thin long parallel wires separated by a distance b are carrying a current i amp each The magnitud of the force per unit length exerted by one wire on the other is bfed ad af ar dr i A ERI dette Gr G YG AR GRI ZE AR Y CIRI GI IN 1 Mo i b 2 Hoi 2Th 3 Hoi 2 b 4 Hoi 2Th

A solenoid of length 0 4 m and having 500 turns of wire carries a current of 3 amp A thin coil having 10 turns of wire and of radius 0 01 m carries a current of 0 4 amp Calculate the torque required to hold the coll in the middle of the solenoid with its axis perpendicular to the axis of solenoid 10 8 10 10 N M 2 6 10 10 N M 3 4 Correct Answer 3 Status unattemptod 6 10 N M 8x10 12 N M

Let a conducting loop connected with a battery be placed in a non uniform magnetic field Then there is 1 no induced emf but current flows in the coil 2 neither induced emf nor current flowing in the coil an induced emf and current flowing in the coil an induced emf but no current flows in the coil 3 4

A wedge of mass M is pushed with an constant acceleration of a gtan along a smooth horizontal surface and a block of mass m is projected down the smooth incline of the wedge with a velocity V relative to the wedge M m A The time taken by the block to cover distance L on the incline plane is B The time taken by the block to cover distance L on the incline plane is C The normal reaction between the block and wedge is mg sect D The horizontal force applied on the wedge to produce acceleration a is M m g tano COMPREHENSION 2L gsine

A constant force F is applied on the rod of mass M and length L placed between two conducting fixed rails in a uniform magnetic field A capacitor C is connected between the two rails as shown in the diagram Neglecting the resistance of the rod and the rails which of the following statement is incorrect 1 Question Type Single Correct Type 2 F 3 M L Acceleration of rod is constant Current in the wire is constant and nonzero Charge on the capacitor is constant

A semicircular insulated conductor of radius 0 5 m lying in x z plane is rotated at uniform angular speed of 4 rad s about an axis passing through one of the ends of the conductor say A in the presence of an external uniform magnetic field B Both the axis of rotation and the magnetic field are normal to the plane of the semicircle If the induced voltage between the ends of the conductor is 10 mV What is the strength of magnetic field in mT Z 0 D B Bo X

he figure below shows the schematic for a mass spectrometer which consists of a velocity selector and a deflection chamber The magnitude of the magnetic field in both the velocity selector and the deflection chamber is 0 0610 T and e electric field between the plates of the velocity selector is 3100 V m If a singly charged ion with a mass of 1 34 x 10 26 kg travels through the velocity selector and into the deflection chamber determine the radius of its trajectory in e deflection chamber x Enter a number article travels straight through a velocity selector how is the force acting on the particle by the electric field related to the force acting on the particle by the magnetic field How is the speed of the moving charged particle elated to the magnitude of the electric and magnetic field What type trajectory does a particle move in when it experiences a force perpendicular to its motion What provides the centripetal force for the ion as it travels in the deflection hamber m B

An electric field applied along the length of a long cylinder produces a polarization P The depolarization field produced in this configuration is a 4 P 3 b 4 P 3 WAT c 2 P d 0 the following Manuell s equations implies the absence of magnetic monopoles

Two identical wires A B have the same length L carry the same current I Wire A is bent into a circle of radius R and wire B is bent to form a square of side a If B B are magnetic induction at the centre of the circle and the centre of square respectively Then B B is 1 2 3 8 8 2 16 4

a A thin conducting wire carries a current I and lies along the x axis from 1 0 0 to x 0 0 Using Biot Savart s law DO NOT USE standard formula find the direction and magnitute of the magnetic field B at a point 0 3 0 due to a length element dll on the wire b Using this expression find the magnetic field at the same point due to the whole wire

If a conducting wire carries a direct current through it the magnetic field associated with the current will be Both inside and outside the conductor Neither inside nor outside the conductor Only outside the conductor Only inside the conductor

With reference to given figure where current enters a circular loop at a point P through a straig and leaves at Q through another straight wire both of which appear to pass through centre v the net magnetic field at the centre of circular coil of radius R Here 1 and 12 are the length two segments of the circular loop 1 Zero 14 2 Ho 2 4 2 R 4 1 Ho 14 2 3 4 R 1 1 4 M Ho 14 2 2R2 4 12

The figure shows a metallic strip whose resistance is such that current flowing through the battery is 4 8 A If B 1 T width of strip 1 cm and number density of free electrons 1029 m then potential difference developed across the width of the strip is V E B Thickness b 1mm

2 A particle of mass m having a charge Q enters into a circular region of uniform magnetic field of radius R with velocity v directed towards the centre The direction of the magnetic field is inwards Then the deviation in the path of the particle will be 1 tan BaR 2 0 1BqR my 3 tan 4 tan 1 3qR 3 58

E A particle of mass m having a charge Q enters into a circular region of uniform magnetic field of radius R with velocity v directed towards the centre The direction of the magnetic field is inwards Then the deviation in the path of the particle will be 1 2 tan 1 BqR mv 3 tan 1BqR mv 2 0 3qR 3 5B field of the contro of a current carrying circular coil of radius R and B is the 4 tan 1

Three long straight wires A B and C are carrying currents as shown in the figure The resultant force on B is directed A B C IAT 2A 3A d d 1 towards A 2 towards C 3 perpendicular to the plane of paper and inward 4 perpendicular to the plane of paper and outward

A current of 5 ampere is flowing in a wire of length 1 5 metres A force of 7 5 N acts on it when it is placed in a uniform magnetic field of 2 Tesla The angle between the magnetic field and the direction of the current is 1 30 3 60 2 45 4 90

28 An electron moving with a speed u along the positive x axis at y 0 enters a region of uniform magnetic field B B which exists to the right of y axis The electron exists from the region after some time with the speed v at co ordinate x y then A v u y 0 B V u y 0 X X x C v u y 0 D v u y 0

29 A charged particle of specific charge charge mass a is released from origin at time t 0 with Z velocity V 1 i 1 in uniform magnetic field B Bi Coordinates of the particle at time Ba are A 2 Vo 2Ba aB Ba C 0 2v VA Ba 28 a B D 28 B a 0 0 2 B C

27 A particle of mass M and charge Q moving with velocity describes a circular path of radius R when subjected to a uniform transverse magnetic field of induction B The work done by the field when the particle completes one full circle is Mv A BQv2rR B R 2xR C zero D BQ2TR

A conducting ring is placed in a uniform external magnetic field present in the space within the ring and perpendicular to plane of ring The magnetic field changes at a constant rate due to which a current of magnitude 4 amp flows in the ring The resistance of parts PQR and PSR are 40 and 80 respectively Then 1 2 S 3 X x x x X X X X R X X M x x P X X Question Type Single Correct Type X X O The emf induced in the ring 48 V Potential difference between P R is 24 V Potential difference between P R is 10 V Potential difference between P Ris zero as

A particle of mass M is attached to two identical springs of unstretched length L and spring constant k The entire system is placed on a horizontal frictionless table as shown in the figure The mass is slightly pulled along the surface of the table and perpendicular to the lengths of the springs and then let go Using the Lagrangian equation s of motion show whether the mass will execute simple harmonic motion If so find the time period 100000000 000000001

A ring of mass m and radius R carrying current I is rotating with angular speed wo Magnetic field B perpendicular to plane of the rin exist in the region as shown Tension 7 developed in the ring is X X 2 Options R mo loB 2 mo 2 B mo aloB mo3 2 B R 2 X R 2

An equilateral triangle ABC of side length a is made The sides AB and AC have resistance per unit length and side BC has resistance per unit length 2 An ideal battery of EMF V is now connected across BC as shown The magnetic field intensity at the centroid of the triangle ABC is n HOV 4 Consider only the field due to sides AB BC and AC of the triangle and neglect the field due to other wires sib ni elaiks T then the value of n is B C

Q 18 A wire carrying current carrying current i has the configuration shown in figure For the magnetic field to be zero at the centre of the circle 0 must be R De 1 1 radian 3 radian 2 2 radian 4 2 radian

PQ and RS are long parallel conductors separated by certain distance M is the midpoint between them The magnitude of net magnetic field at M is 2B Now the current 1 A is switched off Then the magnitude of the field at M now becomes P R O 2B 3 O 4B 3 O 2B OB 2A M S 1A

Two wires A and B are having lengths of 40 cm and 30 cm respectively Both of them are bent in the form of a circle such that current in is passed through A and is through B To have the same magnetic induction at the centre the ratio of i i is 04 3 02 3 03 2 03 4

13 Three long straight wires A B and C are carrying current as shown in figure Resultant force on B is directed A 1AV B 2AV C 2A d d 1 Towards A 2 Towards C 3 Perpendicular to the plane of paper and inward Perpendicular to the plane of paper and outward

A long rectangular loop of width w mass M and resistance R is at rest with the plane of the loop parallel to the ground Immediately to the left of the loop is a region of uniform magnetic field B that points into the screen At time t 0 a constant force F pushes the loop to the left into the magnetic field region as shown in the figure Derive an expression for the speed u of the loop immediately after it enters the magnetic field region in terms of the given variables and the time t U M Ft Bw B 0 0 8 0 0 W

60 The magnetic field at the point O in the given figure is B Hol 3 1 Bra 60 2 Ho 3 1 B Hol 3 1 3 Ana 4 Zero 61 A very long thin strip of metal of width b carries a 3

R 0 5F HH A B 30 Answer C 5 V B A 6H 40 ww Your Attempt S Correct answer VA VB is increasing with time VA VB is decreasing with time VA VB 5V Rate this question

3 The magnetic field in a toroid of 600 turns current of 0 76A and central line radius 0 50m is 2 7 8 x 10 T 4 25 10 2T 1 13 5 x 10 7T 3 1 8 x 10 4T

current carrying conductor at a location shown the figure 1 2 3 4 B H 3 B 1 2 1 21 20 4 a 2 2 B H 3 2ma 2 2 45 Hoi 3 4 2 2 B 3 2a 2 60 S

1 A very long thin strip of metal of width b carries a current I along its length as shown Find the magnitude of magnetic field in the plane of the strip at a distance a from the edge nearest to the point Ho 4 b 1 B b Ho 21 a 2 B H 42 148 b In 4x a 3 B 21 n 1 0 1 2 4 B H 2 211n 4x a a P Telegram ne

A current in a tangent galvanometer produces a deflection of 30 The plane of coil of the tangent galvanometer turned through 90 then deflection will be A B C D 0 45 30 Can t be determined Correct Answer

Aakash Institute 40 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 2 3

A charged particle of mass m and charge q is projected into a uniform magnetic field of induction B with speed v which is perpendicular to B The width of the magnetic field is d The impulse imparted to the particle by the field is d mv qB q m A 3 C X V X qBv mv qB qBd X X X d Correct Answer

45 A semicircular wire of radius r carrying current I 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 Blar 4 Can have the maximum magnitude Blr

An incandescent bulb has a thin filament of tungsten that is heated to high temperature by passing an elect current The hot filament emits black body radiation The filament is observed to break up at random locatio after a sufficiently long time of operation due to non uniform evaporation of tungsten from the filament If the bu is powered at constant voltage which of the following statement s is are true JEE Adv 2016 Paper A The temperature distribution over the filament is uniform B The resistance over small sections of the filament decreases with time C The filament emits more light at higher band of frequencies before it breaks up D The filament consumes less electrical power towards the end of the life of the bulb

A system of two circular co axial coils carrying equal currents I along same direction having equal radius R and separated by a distance R as shown in the figure below The magnitude of magnetic field at the midpoint P is given by 010 1 He 2 4 I 5 5 D R 3 8 1 5 5P 4 0

3 utane Bd 32 If a charged particle goes unaccelerated in a region containing non zero electric and magnetic field then 1 E must be perpendicular to B and velocity v must be along ExB u Bd 2 E must be perpendicular to B and V and must be along v B 4 E is parallel to R and 3 E is parallel to B and V must be along BXE v T 7 Telegramneeta along TL

Questions of this sections are compulsory A cell is connected between the points A and C of a circular conductor ABCD of centre O with angle AOC 60 If B and By are the magnitudes of the magnetic fields at O du to the currents in ABC and ADC respectively the ratio B B is 002 IA B 300 D

Three infinite length wire P Q and R placed parallel to each other net force on 10 cm length of wire Q is 06 108 N 6 10 N 6x10 6N O Zero Im 2A im

1 Consider a bob of mass m and having charge q attached to a light string of length 7 and pivoted at point O It is released from rest at an angle 60 with vertical There are two regions Region I left of line PQ has a uniform and constant magnetic field B directed into the plane of paper Region II right of line PQ has a constant and uniform electric field E directed vertically up as shown Consider no effect of gravity in both the regions BQ RAMAN 60 E constant 0 B AYATHE 2ml A Time taken by particle to cross region I for 1st time is f 5qE B Time taken by particle to cross region I for 2nd time is f 5qE C Angular speed of 1 revolution in magnetic field is 2ml D Angular speed of 2nd revolution in magnetic field is 2ml 13qE 13qE ml

9 Two coils have self inductance L 1 mH respectively The currents in the two 4 coils are increased at the same rate At a certain instant of time both coils are given the same power If I and I are the currents in the two coils at that instant of time respectively then the value 4 of 1 3 18 112 is 4 mH and 2 4 4 1

1 The magnetic field at point P is Hel 1 4 2na Hal 3 8 2ma Hol 2 4 2ra 4 Hol 8 2na 4 1 HRAGTEEES ea fri m fir th 1

Statement 1 As given in diagram the direction of magnetic field at point P is out of the plane of the paper Statement II Right hand thumb rule gives the direction of magnetic field due to current carrying long straight wire A Both statements are true Statement II is the correct explanation of Statement I B Both statements are true Statement II is not correct explanation of Statement I C Statement I is true Statement II is false D Statement I is false Statement II is true