Magnetic Field due to current Questions and Answers

A cube made of wires of equal length is connected to a battery as shown in the figure The magnetic field at the centre of the cube is 0 F Question Type Single Correct Type 1 C 12 01 12TL 6 01

An electron travelling with velocity v enters a region of space in which electric and magnetic fields exist Then the electron goes undeflected for all values of fields 1 If both electric and magnetic field are normal to v 2 If the magnetic field alone is normal to v 3 If both electric and magnetic fields are parallel to v If the electric field along is normal to

A vertical wall is in south north direction A current carrying wire is kept in the wall such that to the west of the wall magnetic field due to wire is towards south Then the wire should be 1 Vertical and current is downwards 2 Horizontal and current is toward west 3 Vertical and current is upward 4 Horizontal and current is towards cont

s Physics R 20 5 outer conductor is hollow of inner radius R and outer radius R The space between the conductors is filled with air The inner and outer conductors are carrying currents of equal magnitudes and in A coaxial cable is made up of two conductors The inner conductor is opposite directions Then the variation of magnetic field with distance from the axis is best plotted as A C B B I 1 1 R R R I 1 IR I 11 R II B D 43 B B 1 I R I R 1 R3 SOLE

A long straight wire carrying current i is bent at its midpoint to form an angle of 45 Find the induction of magnetic field at point P at a distance R from the point of bending b i to KR 45

Figure shows the path of an electron in a region of uniform magnetic field The path consists of two straight sections each between a pair of uniformly charged plates and two half circles The electric field exists only between the plates Pair A BO Pair B 1 Plate I of pair A is at lower potential than plate II of the same pair 2 Plate I of pair B is at lower potential than plate II of the same pair 3 Direction of the electric fields is into the page 0 4 Plate I of pair A is at higher potential than 11

The current is flowing in one direction in two parallel conductors situated in vacuum which type of force will work between them b Attraction b replication c both d None If a particle enters parallel to them in magnetic field What will be the position of particle a Simple line b Circular c Parabola d None

Radius of current carrying coil is R If fractional decreases in field value with respect to centre of the coil for a near by axial point is 1 20 then find axial position of that point R 1 100 2 R R 3 50 30 R 3

1 Vay Find direction of induced current for the given cases Where w r t with respect to time ob observer O Viny If It w r t Motion O e beam accelerated B BEGINNER S BOX 2 VI e beam retarded ija B1 What is the nature of charge on plates of capacitor v Constant 5 INDI i I a beam uniform mo B Le THEOR

4 Statement 1 is False Statement 2 is False STATEMENT 1 When a particle is projected at some angle 90 with horizontal the radius of curvature of its path during the ascent decreases continuously STATEMENT 2 The radius of curvature is the ratio of square of magnitude of the velocity and the acceleration at that point 1 Statement 1 is True Statement 2 is True Statement 2 is a correct explanation for Statement 1 2 Statement 1 is True Statement 2 is True Statement 2 is NOT a correct explanation for Statement 1 3 Statement 1 is True Statement 2 is False 4 Statement 1 is False Statement 2 is False

ALI the path of an electron in a region of uniform magnetic field The path consists of two straight section each between a pair of uniformly charged plates and two half circle The plates are named 1 2 3 4 then F 2 3 4 1 1 and 3 at higher positive potential and 2 and 4 at lower negative potential 2 1 and 3 at lower potential and 2 and 4 at higher potential 5 1 and 4 at higher potential and 2 and 3 at lower potential 1 and 4 at lower potential and 2 and 3 at

A circuit element is placed in a closed box At time t 0 constant current generator supplying a current of 1 amp is connected across the box Potential difference across the box varies according to graph shown in figure The element in the box is A resistance of 20 C inductance of 2H B battery of emf 6V D capacitance of 0 5F V volts 8 2

12 A current i is uniformly distributed over the cross section of a long hollow cylindrical wire of inner radius R and outer radius R Magnetic field B varies with distance r from the axis of the cylinder as B a c B B d 17

d 17 Given figure shows a coil bent with all edges of length 1 m and carrying a current of 1 A There exists in space a uniform magnetic field of 2 T in positive y direction Find the torque on the loop 21

3 An electron is projected with velocity vo in a uniform electric field E perpendicular to the field Again it is projected with velocity vo perpendicular to a uniform magnetic field B If is initial radius of curvature just after entering in the electric field and r2 is initial radius of curvature just after entering in magnetic field then the ratio 1 12 is equal to B a Bv2 E b E c Evo B en Bvo E V 7

33 Infinite number of straight wires each carrying current I are equally placed as shown in the figure Adjacent wires have currents in opposite direction Net magnetic field at point P is 30 a a K 211 12 13 30 a Ho In 2 k 4 3a 11 4 5 Z you y Holin 4 k 4 3a X

The current flows through an equilateral triangular loop of side length If magnetic field at the centroid of the triangula loop is No then find the value of N 6 Correct answer 36

5 OABC is a carrying square loop An electron is projected from the centre of loop along its diagonal AC as shown Unit vector in the direction of initial acceleration will be a k c k y A B CX b d 2

Three long wires each carrying current i are placed parallel to each other The distance between I and II is 3d between II and III is 4 d and between III and I is 5d Magnetic field at side of wire II is 1 2 3 4 5 24rd 10poi 24nd 15pi 24nd 20 i 3d Sd 43 I

At a place horizontal and vertical components of earth s magnetic field are as follows BH 3 G 10 west of north By 1 G vertically downward Then dip angle and declination are respectively A B C D 0 10 W 30 10 E 45 10 W 30 10 W

9 An air filled toroidal solenoid has a mean radius of 15 0 cm and a cross sectional area of 5 00 cm When the current is 12 0 A the energy stored is 0 390 J How many turns does the winding have

upward direction y direction is placed near the surface of earth as shown in figure Neglect the earth s magnetic field y a 0 A At some time t a particle is at point A a 0 and moving towards origin with velocity V If the acceleration of particle at point A is 2g in downward direction then particle is negatively charged INCORRECT particle is positively charged CORRECT ANSWER magnitude of charge on the particle is Tamg MOVI

1 12 hree long straight wires are located at the corners of an equilateral triangle of side L 30 cm as shown in the figure above I 5 A 2 8A I3 2 A What is the magnetic field due to I and I at the position of I3 i T L What is the magnetic force per meter on the wire with I3 N m i 1

The figure shows an end view of two long parallel wires perpendicular to the x y plane Each wire carries a current 1 5 A but in opposite directions Calculate the net magnetic field at point P if a 0 3 m and s 0 4 m y a a I XI X P X

SolveLancer Test There is a ring of mass m radius R and has a charge uniformly distributed charge q The ring is cut into half and rotate about one of ends as shown The ring mass an S shape and axis is perpendicular to plane of half rings SolveLancer Test Loo b 2qR w c qR w qR w d 27 Find the magnetic moment of this arrangement a qR w

Figure shows circular region of radius R 3 m in which upper half has uniform magnetic field B 0 2 k T and lower half has uniform magnetic field B 0 2 KT A very thin parallel beam of point charges each having mass m 2gm speed v 0 3 m sec and charge q 1mC are projected along the diameter as shown in figure A screen is placed perpendicular to initial velocity of charges as shown If the distance between the point on screen where charges will strike is 4X meters then calculate X x R R Screen

The magnetic moment of a thin round loop with current if the radius of the loop is equal to R 100 mm and the magnetic field at its centre is equal to B 6 0 T is 30 x 10 A m Find the value of x

A conducting wire bent in the form of a parabola y 2x carries a current i 2A as shown in figure This wire is placed in a uniform magnetic field B 4k Tesla The magnetic force on the wire in region 0 x 2m is in Newton y m A 2 B x m

The magnetic flux density in a region of free space is given as B 6xax 9yay 3za T the force on the side 4 of rectangular loop shown in Figure it lies in the plane z 30 az None of the choices 180 az 2 90 az 2 SA

A metal strip 6 50 cm long 0 850cm wide and 0 760mm thick moves with constant velocity through a uniform magnetic field B 1 20mT directed perpendicular to the strip as shown in the figure A potential difference of 3 90 V is measured between points and y across the strip Calculate the speed v

Several a particles of different speeds enter a uniform magnetic field confined into cylindrical region If all the a particles enter the field radially what can you say about time intervals spent by them in the magnetic field B A Faster is the particle lesser is the time B Slower is the particle lesser is the time C Slower is the particle greater is the time D The time is same for all the particles

An electron is travelling with velocity u 3 5 m s in a magnetic field B 61 43 tesla What is the magnitude and direction of the force F acting on the electron A 18e N along ve z axis B 18e N along ve z axis C 36e N along ve z axis D 54e N along ve z axis

0 Two circular coils are made of two identical wires of same length and carry same current If the number of turns of the two coils are 4 and 2 then the ratio of magnetic induction at the centres will be 2 1 2 1 2 i 3 1 14 4 1

B 4 Consider a quarter circular conducting ring of large radius r with its centre at the origin where a magnetic dipole of moment m is placed as shown in the figure If the ring rotates at a constant angular velocity a about the y axis electromotive force induced between its ends is a Zero c mw 4 r b mw 2 r d mw 8 r

A long straight wire carries a current of 40 A in a region where a uniform externa magnetic field has a 30 T magnitude and is parallel to the current What is the magnitude of the resultant magnetic field at a point that is 4 6 cm from the wire a 176 48 uT Ob 30 00 uT Oc 374 21 T d 62 27 HT Oe 37 81 T 13

0 Consider two long thin conductors A and B each carrying current I as shown in the figure Co sidering A to be fixed which of the following statements is correct y Z B X A B experiences a net force along axis B B experiences a net anticlockwise torque C B experiences a net force along r axis D B experiences a net clockwise torque

A coil of 100 turns kept in magnetic field B 0 2T carries a current of 2A as shown in figure Torque on coil and which side of coil comes out from the plane of the paper A 1 0 16 N m BC side comes out from plane of paper 2 0 16 N m AD side comes out from plane of paper 3 0 32 N BC side comes out from plane of paper 4 0 32 N m AD side comes out from plane of paper N D 8 cm 10 cm B S

2 You are given 13 0 m of thin wire You form the wire into a circular coil with 50 turns If this coil is placed with its axis par on allel to a 0 12 T magnetic field what is the flux through the coil

A circular coil carrying current I is placed in a region of uniform magnetic field acting perpendicular to a coil as shown in the figure Mark correct option X X X X X X X X X X X X X X X X X X coil contracts X coil moves left X X X coil expands CORRECT ANSWER XT X X X X X X X X x X X XXX X X X

5 equal zero So one in which A circular coil of 100 turns and effective diameter 20 cm caries a current of 1A It is to turned in a magnetic field B 3T from a position in which equal 180 The work required in this process is A 0 J C 4 J B 2 J D 6 J

A 250KVA single phase transformer has 250 turns in primary and 40 turns in secondar windings The primary is connected to 1500 volts 50 Hz mains Calculate i Primary and secondary currents on full load ii Secondary emf iii Max flux in the core

The pressure does the lateral surface of a long straight solenoid with n turns per unit length experience when a current I flows through it is Hon 1 Find k k

A metal bar of mass m slides frictionlessly on two parallel conducting rails a distance 1 apart A resistor R is connected across the rails and a uniform magnetic field B pointing into the page fills the entire region TE a If the bar moves to the right at speed v what is the current in the resistor In what direction does it flow b What is the magnetic force on the bar R www

A thin rod is bent in the shape of a small circle of radius r If the charge per unit length of the rod is c and if the circle is rotated about its axis at a rate of n rotations per second the magnetic induction a point on the axis at a large distance y from the centre is Option A B C Howr no y 2 m no y3 Hor no 4 y Hor no Rate this que

Consider the mass spectrometer shown schematically in the figure below The electric field between the plates of the velocity selector is 7600 V m and the magnetic fields in both the velocity selector and th leflection chamber have magnitudes of 0 0300 T Calculate the radius r of the path for a singly charged ion with mass m 3 95 x 10 26 kg m x x x P Bo in x x xx x Photographic plate x x x x x Bin X X Velocity selector x x X x xx x x x x x X x

A straight wire carries a current of 50 A and the loop is moved to the right with a constant velocity v 10 m s the induced emf in the loop at the instant when x 0 2 m is Take a 0 1 m and assume that the loop has a large resistance

66 A magnet 20 cm long with its poles concentrated at its ends is placed vertically with its north pole on the table At a point due 20 cm south magnetic of the pole a neutral point is obtained If H 0 3 G then the pole strength of the magnet is approximately a 185 ab amp cm c 18 5 ab amp cm b 185 amp m d 18 5 amp cm

A circular current carrying loop of mass 100 g is free to rotate about the axis yy If i 1 A and B 0 1 Tthen the time period of small oscillation will be X xix X TS 2TS 3TS 460 X X X X X

A loop of wire has the shape shown in the drawing The top part of the wire is bent into a semicircle of radius r 0 10 m The normal to the plane of the loop is parallel to a constant magnetic field p 0 of magnitude 0 67 T What is the change AO in the magnetic flux that passes through the loop when starting with the position shown in the drawing the semicircle is rotated through half a revolution

c29p5 Consider the circuit in the figure b The curved segments are arcs of circles of angle 250 and radii a 14 cm and b 7 cm The straight segments are along radii Find the magnetic field B at point P the center of curvature assuming a current 9 A clockwise in the circuit Positive out of page and negative into page Submit Answer Incompatible units No conversion found between cm and the required units A i H R2 R C J a Tries 0 3 Previous Tries J D a 0 P b b