Magnetic Effects of Current — JEE Main PYQs

Given below are two statements:

Statement (I) : When currents vary with time, Newton's third law is valid only if momentum carried by the electromagnetic field is taken into account.

Statement (II) : Ampere's circuital law does not depend on Biot-Savart's law.
In the light of t …

A square loop of edge length 2 m carrying current of 2 A is placed with its edges parallel to the $x-y$ axis. A magnetic field is passing through the $x-y$ plane and expressed as $\vec{B}=B_0(1+4x)\hat{k}$, where ${\mathrm{B}}_0=5\mathrm{T}$. Then net magnetic force …

A proton and a deutron ( $\mathrm{q}=+\mathrm{e},m=2.0\mathrm{u}$ ) having same kinetic energies enter a region of uniform magnetic field $\overrightarrow{\mathrm{B}}$, moving perpendicular to $\overrightarrow{\mathrm{B}}$. The ratio of the radius $r_d$ of deutron pat …

The magnetic field at the centre of a wire loop formed by two semicircular wires of radii ${\mathrm{R}}_1=2\pi \mathrm{m}$ and $R_2=4\pi \mathrm{m}$ carrying current $\mathrm{I}=4\mathrm{A}$ as per figure given below is $\alpha \times 10^{-7}\mathrm{T}$. The val …

Two particles X and Y having equal charges are being accelerated through the same potential difference. Thereafter they enter normally in a region of uniform magnetic field and describes circular paths of radii $R_1$ and $R_2$ respectively. The mass ratio of X and Y is :

A charge of $4.0\mu \mathrm{C}$ is moving with a velocity of $4.0\times 10^6{\mathrm{ms}}^{-1}$ along the positive y-axis under a magnetic field $\overrightarrow{\mathrm{B}}$ of strength $(2\hat{\mathrm{k}})$ T. The force acting on the charge is …

A proton moving with a constant velocity passes through a region of space without any change in its velocity. If $\overrightarrow{\mathrm{E}}$ and $\overrightarrow{\mathrm{B}}$ represent the electric and magnetic fields respectively, then the region of space may have :
(A) …

Two long, straight wires carry equal currents in opposite directions as shown in figure. The separation between the wires is 5.0 cm. The magnitude of the magnetic field at a point P midway between the wires is ______ $\mu \mathrm{T}$
(Given: …

The magnetic potential due to a magnetic dipole at a point on its axis situated at a distance of 20 cm from its center is $1.5\times 10^{-5}\mathrm{Tm}$. The magnetic moment of the dipole is $\_\_\_\_$ ${\mathrm{Am}}^2$.
(Given : …

A rigid wire consists of a semicircular portion of radius R and two straight sections. The wire is partially immerged in a perpendicular magnetic field $\mathrm{B}={\mathrm{B}}_0\hat{\mathrm{j}}$ as shown in figure. The magnetic force on the wire if it has a current $i$ is :

An electron moves through a uniform magnetic field $\vec{B}=B_0\hat{i}+2B_0\hat{j}$ T. At a particular instant of time, the velocity of electron is $\vec{u}=3\hat{i}+5\hat{j}$ m/s. If the magnetic force acting on electron is $\vec{F}=5e\hat{k}$ N, where e is the charge …

A regular polygon of 6 sides is formed by bending a wire of length $4\pi$ meter. If an electric current of $4\pi \sqrt{3}$ A is flowing through the sides of the polygon, the magnetic field at the centre of the polygon would be $\mathrm{x}\times 10^{-7}\mathrm{T}$. The …

The current of 5 A flows in a square loop of sides 1 m is placed in air. The magnetic field at the centre of the loop is $\mathrm{X}\sqrt{2}\times 10^{-7}\mathrm{T}$. The value of X is

Two insulated circular loop A and B radius ' a ' carrying a current of ' I ' in the anti clockwise direction as shown in figure. The magnitude of the magnetic induction at the centre will be :

The horizontal component of earth's magnetic field at a place is $3.5\times 10^{-5}T$. A very long straight conductor carrying current of $\sqrt{2}A$ in the direction from South east to North West is placed. The force per unit length experienced by the conductor is ___\ …

A uniform magnetic field of $2\times 10^{-3}$ T acts along positive Y-direction. A rectangular loop of sides 20 cm and 10 cm with current of 5 A is Y-Z plane. The current is in anticlockwise sense with reference to negative X axis. Magnitude and direction of the torque is:

Two circular coils P and Q of 100 turns each have same radius of $\pi \mathrm{cm}$. The currents in P and R are 1 A and 2 A respectively. P and Q are placed with their planes mutually perpendicular with their centers coincide. The resultant magnetic field induction at the center …

The ratio of magnetic field at the centre of a current carrying coil of radius $r$ to the magnetic field at distance $r$ from the centre of coil on its axis is $\sqrt{x}:1$. The value of x is $\_\_\_\_$

A charge particle moving in magnetic field B, has the components of velocity along B as well as perpendicular to B. The path of the charge particle will be

The magnetic intensity at the centre of a long current carrying solenoid is found to be $1.6\times 10^3{\mathrm{Am}}^{-1}$. If the number of turns is 8 per cm, then the current flowing through the solenoid is $\_\_\_\_$ A.

A proton with a kinetic energy of 2.0 eV moves into a region of uniform magnetic field of magnitude $\frac{\pi }{2}\times 10^{-3}$ T. The angle between the direction of magnetic field and velocity of proton is $60^{\circ }$. The pitch of the helical path taken by the proton is ____ …

A straight wire carrying a current of 14 A is bent into a semicircular arc of radius 2.2 cm as shown in the figure. The magnetic field produced by the current at the centre (O) of the arc is ______ $\times 10^{-4}$ T

An electron is moving along the positive x -axis. If the uniform magnetic field is applied parallel to the negative z -axis. then
A. The electron will experience magnetic force along positive y -axis
B. The electron will experience magnetic force along negative y -axis
C. The ele …

A straight wire AB of mass 40 g and length 50 cm is suspended by a pair of flexible leads in uniform magnetic field of magnitude 0.40 T as shown in the figure. The magnitude of the current required in the wire to remove the tension in the supporting leads is $\_\_\_\_$ A. (Take …

An electron in a hydrogen atom revolves around its nucleus with a speed of $6.76\times 10^6$ ms${}^{-1}$ in an orbit of radius $0.52$ Å. The magnetic field produced at the nucleus of the hydrogen atom is ______ T.

A long straight wire of circular cross-section (radius a) is carrying steady current I. The current I is uniformly distributed across this cross-section. The magnetic field is

Two identical circular wires of radius 20 cm and carrying current $\sqrt{2}$ A are placed in perpendicular planes as shown in figure. The net magnetic field at the centre of the circular wire is $\times 10^{-8}$ T. (Take $\pi =3.14$)

An electron is allowed to move with constant velocity along the axis of current carrying straight solenoid.
A. The electron will experience magnetic force along the axis of the solenoid.
B. The electron will not experience magnetic force.
C. The electron will continue to move alo …

Find the magnetic field at the point P in figure. The curved portion is a semicircle connected to two long straight wires.

A charge particle of $2\mu \mathrm{C}$ accelerated by a potential difference of 100 V enters a region of uniform magnetic field of magnitude 4 mT at right angle to the direction of field. The charge particle completes semicircle of radius 3 cm inside magnetic field. The mass o …

Two long straight wires P and Q carrying equal current 10A each were kept parallel to each other at 5 cm distance. Magnitude of magnetic force experienced by 10 cm length of wire P is ${\mathrm{F}}_1$. If distance between wires is halved and currents on them are doubled, force …

A circular loop of radius $r$ is carrying current I A. The ratio of magnetic field at the centre of circular loop and at a distance r from the center of the loop on its axis is :

A long solenoid is formed by winding 70 turns cm${}^{-1}$. If 2.0 A current flows, then the magnetic field produced inside the solenoid is ______ (${\mu }_0=4\pi \times 10^{-7}$ TmA${}^{-1}$)

A single turn current loop in the shape of a right angle triangle with sides $5$ cm, $12$ cm, $13$ cm is carrying a current of 2 A. The loop is in a uniform magnetic field of magnitude 0.75 T whose direction is parallel to the current in the 13 cm side of the loop. The magnitude …

A solenoid of 1200 turns is wound uniformly in a single layer on a glass tube 2 m long and 0.2 m in diameter. The magnetic intensity at the center of the solenoid when a current of 2 A flows through it is:

Two long parallel wires carrying currents 8 A and 15 A in opposite directions are placed at a distance of 7 cm from each other. A point P is at equidistant from both the wires such that the lines joining the point P to the wires are perpendicular to each other. The magnitude of m …

A single current carrying loop of wire carrying current I flowing in anticlockwise direction seen from +ve $z$ direction and lying in xy plane in shown in figure. The plot of $\hat{j}$ component of magnetic field (By) at a distance 'a' (less than radius of the coil) and on $yz$ p …

The magnitude of magnetic induction at mid-point O due to current arrangement as shown in Fig will be :

The electric current in a circular coil of four turns produces a magnetic induction 32 T at its centre. The coil is unwound and is rewound into a circular coil of single turn, the magnetic induction at the centre of the coil by the same current will be:

As shown in the figure, a current of 2A flowing in an equilateral triangle of side $4\sqrt{3}\mathrm{cm}$. The magnetic field at the centroid O of the triangle is :
(Neglect the effect of earth's magnetic field.)

A current carrying rectangular loop PQRS is made of uniform wire. The length $\mathrm{PR}=\mathrm{QS}=5\mathrm{cm}$ and $\mathrm{PQ}=\mathrm{RS}=100\mathrm{cm}$. If ammeter current reading changes from I to 2 I, the ratio of magnetic forces per unit length on the wire PQ due …

The magnetic moments associated with two closely wound circular coils $A$ and $B$ of radius $r_A=10\mathrm{cm}$ and $r_B=20\mathrm{cm}$ respectively are equal if: (Where ${\mathrm{N}}_{\mathrm{A}},{\mathrm{I}}_{\mathrm{A}}$ and …

A massless square loop, of wire of resistance $10\Omega$. supporting a mass of I g. hangs vertically with one of its sides in a uniform magnetic field of $10^3\mathrm{G}$, directed outwards in the shaded region. A dc voltage V is applied to the loop. For what value of V . …

A long conducting wire having a current I flowing through it, is bent into a circular coil of N turns. Then it is bent into a circular coil of $n$ turns. The magnetic field is calculated at the centre of coils in both the cases. The ratio of the magnetic field in first case to th …

As shown in the figure, a long straight conductor with semicircular arc of radius $\frac{\pi }{10}$ m is carrying current $I=3$ A. The magnitude of the magnetic field at the center O of the arc is:
(The permeability of the vacuum $=4\pi \times 10^{-7}$ NA${}^{-2}$)

A wire X of length 50 cm carrying a current of 2 A is placed parallel to a long wire Y of length 5 m. The wire Y carries a current of 3 A. The distance between two wires is 5 cm and currents flow in the same direction. The force acting on the wire Y is :

As shown in the figure, a metallic rod of linear density $0.45\mathrm{kg}{\mathrm{m}}^{-1}$ is lying horizontally on a smooth incline plane which makes an angle of $45^{\circ }$ with the horizontal. The minimum current flowing in the rod required to keep it stationary, when …

A triangular shaped wire carrying 10A current is placed in a uniform magnetic field of 0.5 T , as shown in figure. The magnetic force on segment CD is (Given $\mathrm{BC}=\mathrm{CD}=\mathrm{BD}=5\mathrm{cm}$ ).

The magnetic field at the center of current carrying circular loop is ${\mathrm{B}}_1$. The magnetic field at a distance of $\sqrt{3}$ times radius of the given circular loop from the center on its axis is ${\mathrm{B}}_2$. The value of ${\mathrm{B}}_1/{\mathrm{B}}_2$ will be

Two charged particles, having same kinetic energy, are allowed to pass through a uniform magnetic field perpendicular to the direction of motion. If the ratio of radii of their circular paths is $6:5$ and their respective masses ratio is $9:4$. Then, the ratio of their char …