Magnetic Field due to current Questions and Answers

Two sliding rods each of length is moving with velocity v and 2v as shown in the given figure in presence of external magnetic field B The current in the circuit is 1 2 3 2v Blv R 3Blv 2R 2Blv R Bly X R X X X X X X Rx B X v l X X X

There is a magnetic field acting in a plane perpendicular to the sheet of paper downward into the paper shown in figure a particle in vacuum moves in the plane of paper from left to right as shown in figure T path indicated by the arrow could be travelled by 1 Proton 3 Electron Cash Educational Servicen XX X X X X X X X X X X X X XXX XX X X XXXXX XX XX X X X X X XXXXX XXX 2 4 Neutron Alpha particle

A proton an electron a neutron an a particle and an unknown particle enter in a region of uniform magnetic field with equal momenta Figure shows paths marked 1 to 5 followed by these particles Identify which path corresponds to which particle B 5 4

The dipole moment of a circular loop carrying a current is m and the magnetic field at the centre of the loop is B When the dipole moment is doubled by keeping the current constant the magnetic field at the centre of the loop is B Then what is the ratio B B2 Take 2 1 41

A metal rod slides on conducting rails as shown in figure The circuit area is perpendicular to magnetic field with B 0 2 T If the resistance of circuit is 4 0 the force needed to move the rod as indicated with a constant speed of 5 m s will be equal to X X 4923 X X X O 5 x 10 N O 4 10 N 9 10 4 N 2x 10 3 N X X X X V 5 m s

A cyclotron s oscillating frequency is 10 MHz The radius of dee is 60 cm What is the kinetic energy of proton produced by the accelerator if the magnetic field is 0 65 Tesla O 7 28 MeV O 12 6 keV O 10 5 eV O 19 4 eV

A charged particle of speci charge 0 2 C kg has velocity of 21 3 m s at some instant in uniform magnetic field 51 21 T What is the acceleration of the particle at this instant O 3 8 k m s O 1 2 k m s 2 2 k m s O 12 km s

A moving coil galvanometer coil has a coil of area A number of turns N The radial magnetic field present is B the moment of inertia of the coil is I about its rotation axis The torque is applied by the magnetic field on the coil of the galvanometer when current Io passes through it and produces a deflection of T 2 of the pointer Then answer the following questions based on the paragraph Then the value of torsionl constant of the spring is

L is a circular ring made of a uniform wire currents enters and leaves the ring through straight conductors which if produces would have passed through the centre C of ring The magnetic field at C i L i due to the straight conductors is zero ii due to the loop is zero iii due to the loop is proportional to iv due to loop is proportional to 0

A proton a deuteron and an alpha particle w same kinetic energy enter in a region of unifo magnetic field moving at right angles to magne field What is the ratio of radii of their circular pat 1 1 2 1 2 1 2 2 3 2 1 1 4 2 2 1

8 A square frame of side 1 carries a current I and produces a magnetic field B at its centre If the same current is passed through a circular coil having the same perimeter as the square frame it produces a B will be field B at its centre Then B a 8 2 b 8 2 c 9 1 2 d 16 2

A long straight wire carries the current along ve x direction Consider four points in space A 0 1 0 B 0 1 1 C 1 0 1 and D 1 1 1 Which of the pairs will have the same magnitude of magnetic field

A rigid wire consists of a semicircular portion of radius R and two straight sections AB and CD The wire has partially emerged in a perpendicular magnetic field Bo as shown in figure What is the force on the wire if it carries a current B A R R R O D C B I

What is magnetic field at point O if the wire carries a current and straight parts are very long z axis 021 24 Hol 2R O Hol 4R C T 0 214 2R Ho 1 11 x axis y axis

4 The force between two parallel wire is 2 x 10 7 Nm which are placed 1 m apart to each other in vacuum The electric current flowing through the wires is a 1 A c 5 106 A b zero d 2 10 7A

Two ferromagnetic materials X and Y have Hysteresis curves of the shapes shown below H H X and Yare suitable for making permanent magnets X is more suitable for permanent magnet while y for electromagnet O X is more suitable as electromagnet and Yas permanent magnet O Hysteresis loss is more for X than Y

Online Mock Test Series for NEET 2020 10 Current is flowing in a long wire which is turned by 90 at O Distance of a point P from Ois d Magnetic field at Pis e 24 4x d 3 2 1 P 2 2 1 401 d 4 None of these

questions Each question has 4 choices 1 2 3 Read More The magnetic dipole moment of current loop as shown in figure is Y Semicircle Z axis L 90 X

When a proton has a velocity v 2 3 106 m s it experiences a force X 3 X F 1 28 10 k N When its velocity is along z axis it experiences a force along x axis The magnetic field in the region i in tesla a 0 47 c 0 47 b 0 4 067

The force on a current carrying square loop PQRS due to infinitely long current carrying wire in its plane as shown in the figure is lo 2a O Hollo 2 O Hollo attractive A Hollo repulsive O Hollo 12T PL Hollo I a attractive R S a

questions Each question has 4 choices 1 2 Read More Current is moving in a regular hexagon shaped loop of side length a What is the magnetic field at the centre of hexagon O O 2 olo 3 olo a 3Holo

The radius of a circular current carrying coil is R At what distance from the centre of the coil on its axis the intensity of magnetic field will be 1 3 3 times to that at centre R R 2 2 R

A solid sphere of uniform density and radius R applies a gravitational force of attraction equal to F on a particle placed at a distance 3R from the center of the sphere A spherical cavity of radius R 2 is now made in the sphere as shown in the figure The sphere with cavity now applies a gravitational force F2 on the same particle The ratio F F1 is A Choose only 1 answer 9 50 3R 41 A

18 A dip circle is placed in geographic meridian at a place where dip and declination are known to be respect 30 and 45 What dip will be given by dip circle 1 tan 3 tan 6 2 3 3 2 tan 4 tan IN 2 3 2

becomes ww do Change N Total ne of Twins in p Very Short Answer Type Questions 16 As soon as current is switched on in a high voltage wire the bird sitting on it flies away Why induce emf current 1814 E 100 2 20

The conductor AD moves to the right in a uniform magnetic field directed into the paper X XD X X X X X X X X X X X X X X X B X X X X X X X X X X XXX X X X X X X X V X X X X X X X X X x A X X X X X X X X X X X VE CAREER POINT CP Tower IPIA Road No 1 Kota Raj 0744 1 The free electrons in conductor move toward A D will acquire a positive potential with respect to A 3 If D and A are joined by a wire externally a current will flow from A to D in wire

A small square loop of wire of side is placed inside a large square loop of wire of side L L The loop are coplanar and their centre coincide The mutual inductance of the system is proportional to A 1 L C L I LEBT D PIL 1 1

136 A voltmeter gives full scale deflection at 20 V To convert it into a voltmeter which gives a full scale deflection at 200 V the voltmeter should be connected R be the initial resistance of the voltmeter to a 1 Shunt resistor of voltmeter R 9 R 2 Shunt resistor of 10 voltmeter in parallel with the in parallel with the 3 Resistor of 9R in series with the voltmeter Docistor of 10R in series with the voltmeter

ring is dropped down keeping its plane perpendicular to a constant and horizontal magnetic field The ring enters the field region at t 0 and completely emerges out at t T second The current in the ring varies as 1 3 ph At 2 4 t

A long wire carrying a steady current is bent into a circular loop of one turn The magnetic field at the center of the loop is B It is then bent into a circular coil of n turns The magnetic field at the center of this coil of n turns will be 1 Point nB n B 2nB 2n B

1 A thin bar magnet is cut into two equal parts as shown in the figure The ratio of moment of inertia to the magnetic moment of each part will become as compare to original magnet 1 3 1 C 2 4 1

a State Biot Savart s law and express this law in the vector form b Two identical circular coils P and Q each of radius R carrying currents 1A and 3 A respectively are placed concentrically and perpendicular to each other lying in the XY and YZ planes Find the magnitude and direction of the net magnetic field at the centre of the coils Coil P carries clockwise current when seen from right coil Q carries anti clockwise when seen from top P I I Q yz plane R R

A straight thick long wire of uniform cross section of radius a is carrying a steady current I The current is uniformly distributed across the cross section Use Ampere s circuital law to obtain magnetic field at a distance r from the center of cross section for i r a and ii r a

losed circuit consists of a source of constant emf of 10 V connected to a resistor of resistance 10 Q and inductor of inductance 0 1 H At tim the inductance was abruptly decreased to 0 01 H Find the current in the circuit at t 0 immediately after change in A

xample 2 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 00 a T dx X

The current in a coil of self inductance 4 H is changing according to the law sint Find out the amount of TC magnetic energy in J stored in the inductor during the time interval t 0 to t 4 S 2 A

Q 29 figure A conductor lies along the Z axis at 1 5 1 5 m and carries a fixed current of 10 0 A in a direction see for a field 3 0 x 10e02a T Find the power required to move the conductor at constant speed to x 2 0 m y 0 min 5 x 10 Assume parallel motion along the x axis our Answer 85 W otion 1 57 W tion 2 17 W 2 0 1 5 ED 1 5

When a conductor is rotated in perpendicular magnetic field then its free electrons initially 1 Move along field direction 2 Move at right angles to field direction 3 Remain stationary 4 Move opposite to field direction

1 3 A rod of mass m and length is in contact vertical rails connected with resistance R on other end a horizontal magnetic field B perpendicular to the rod Find terminal velocity of rod while falling down 3 mgR B 1 3mgR 0 12 2 4 2mgR B 1 4mgR 2 2 3 q q DY CL Even in the

37 A coil of single turn is wrapped around a sphere of radius r and mass m The plane of the coil is parallel to the inclined plane and lies in the equatorial plane of the sphere If the sphere is in rotational equilibrium the value of strength of uniform magnetic field in vertically downward direction is current in the coil is I as shown in figure 1 2 2 mg lr mgsine Tlr mg Tlr sin 0 B 00

Consider the mass spectrometer as shown in figure The electric field between plates is EV m and the magnetic field in both the velocity selector and in the deflection chamber has magnitude B Find the radius r for a singly charged ion of mass m in the deflection chamber e OB E OB Question Type Single Correct Type

e AB of mass m and length is placed over two smooth conducting rails P and Q If the switch shown as closed at t 0 find the velocity of rod AB as a function of time E BI S www R 1 e B 1 1 mR B X F Bil Figure 5 53 X X X P Q

As shown in the figure a rectangular loop of a conducting wire is moving away with a constant velocity v in a perpendicular direction from a very long straight conductor carrying a steady current I When the breadth of the rectangular loop is a very small compared to its distance from the straight conductor how does the e m f E induced in the loop vary with time t LEAT Ex I V WB JEE 2018 E x 1 t 1

The conductor AD moves to the right in a magnetic field directed into the paper Then D X X XOX B X X X X X ONO the free electrons in Ad will move towards A D will acquire a positive potential with respect to A If D and A are joined by a conductor externally A current will flow from A to D in AD

A wire ABCDEF is bent in the form as shown in figure The wire carries a current I and is placed in a uniform magnetic field of induction B parallel to positive Y axis If each side is of length L the force experienced by the wire will be B Z L D I L F a IBL along the positive Z direction b IBL along the negative Z direction c 2IBL along the positive Z direction d 2IBL along the negative Z direction Y

metal rod of length 1 moving with an angular velocity w and velocity of its centre is v Find potential different between points A and B at the hown in figure A uniform magnetic field of strength B exist perpendicular to plane of paper A ed Bvl 1 Bvl Bwl 2 Bwl Bwl 2 Bvl Bw 5 2 B V

Two cables of copper are of equal lengths One of them has a single wire of area of cross section A while other has 10 wires of cross sectional area A 20 each Give their suitability for transporting A C and D C 10 1 Only multiple strands for A C either for D C 2 Only multiple strands for A C only single strand for D C 3 Only single strand for D C either for A C 1 Only single strand for A C either for D C

Two very long straight parallel wires carry steady currents I and 1 The distance between the wires d At a certain instant of time a point charge q is at a point equidistant from the two wires in the plane of the wires Its instantaneous velocity v is perpendicular to this plane The magnitude of the force due to the magnetic field acting on the charge at this instant is A Holqv 2nd B A particle with charge Q and mass m enters a magnetic field of magnitude B 9 Hlqv C nd 2 Jqv D nd Zero

and B through which a ring having charge 9 passes through without touching the shell The flux through spherical shell is Find the 380 radius of the ring a R 2 c 0 5 R TX 71 A B R b 2 R d None of these

A long wire carrying a steady current is bent into circular loop of one turn The magnetic field at the centr of the loop is B It is then bent into a circular coil of turns The magnetic field at the centre of this coil of turns will be 1 nB 2 n B 3 2nB 4 2n B