Magnetic Effect of Current

A current of 1 A is flowing on the sides of an equilateral triangle of side 4.5 \(\times\) 10-2 m. The magnetic field at the center of the triangle will be :

The dipole moment of a circular loop carrying a current I, is m and the magnetic field at the centre of the
loop is B1. When the dipole moment is doubled by keeping the current constant, the magnetic field at the
centre of the loop is $${{B...

An electron, a proton and an alpha particle having the same kinetic energy are moving in circular orbits of
radii re, rp, r\(_\alpha\) respectively in a uniform magnetic field B. The relation between re, rp, r\(_\alpha\) is:

A negative test charge is moving near a long straight wire carrying a current. The force acting on the test charge is parallel to the direction of the current. The motion of the charge is :

In a certain region static electric and magnetic fields exist. The magnetic field is given by \(\overrightarrow B = {B_0}\left( {\widehat i + 2\widehat j - 4\widehat k} \right)\) . If a test charge moving with a velocity $$\overrightarrow ...

A magnetic dipole in a constant magnetic field has :

To know the resistance G of a galvanometer by half deflection method, a battery of emf VE and resistance R is used to deflect the galvanometer by angle \(\theta\). If a shunt of resistance S is needed to get half deflection then G, R and S...

A magnetic dipole is acted upon by two magnetic fields which are inclined to each other at an angle of 75o. One of the fields has a magnitude of 15 mT. The dipole attains stable equilibrium at an angle of 30o with this field. The magnitude ...

Two identical wires \(A\) and \(B,\) each of 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 \({B_A}\) and \({B_B}\) are the values o...

Two long current carrying thin wires, both with current \(I,\) are held by insulating threads of length \(L\) and are in equilibrium as shown in the figure, with threads making an angle \('\theta '\) with the vertical. If wires have mass $$...

A rectangular loop of sides \(10\) \(cm\) and \(5\) \(cm\) carrying a current \(1\) of \(12A\) is placed in different orientations as shown in the figures below :

If there is a uniform magnetic field of \(0.3\) \(T\) in the positive \(z\) ...

A conductor lies along the \(z\)-axis at \(- 1.5 \le z < 1.5\,m\) and carries a fixed current of \(10.0\) \(A\) in \(- {\widehat a_z}\) direction (see figure). For a field $$\overrightarrow B = 3.0 \times {10^{ - 4}}\,{e^{ - 0.2x}}\,\,{\...

A charge \(Q\) is uniformly distributed over the surface of non-conducting disc of radius \(R.\) The disc rotates about an axis perpendicular to its plane and passing through its center with an angular velocity \(\omega .\) As a result of t...

Proton, deuteron and alpha particle of same kinetic energy are moving in circular trajectories in a constant magnetic field. The radii of proton, denuteron and alpha particle are respectively \({r_p},{r_d}\) and \({r_\alpha }\). Which one...

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:

Two long parallel wires are at a distance \(2d\) apart. They carry steady equal currents flowing out of the plane of the paper as shown. The variation of the magnetic field \(B\) along the line \(XX'\) is given by

A current loop \(ABCD\) is held fixed on the plane of the paper as shown in the figure. The arcs \(BC\) (radius \(= b\)) and \(DA\) (radius \(=a\)) of the loop are joined by two straight wires \(AB\) and \(CD\). A steady current \(I\) is fl...

A current loop \(ABCD\) is held fixed on the plane of the paper as shown in the figure. The arcs \(BC\) (radius \(= b\)) and \(DA\) (radius \(=a\)) of the loop are joined by two straight wires \(AB\) and \(CD\). A steady current \(I\) is fl...

A horizontal overhead powerline is at height of \(4m\) from the ground and carries a current of \(100A\) from east to west. The magnetic field directly below it on the ground is
$$\left( {{\mu _0} = 4\pi \times {{10}^{ - 7}}\,\,Tm\,\,{A^{...

A charged particle with charge \(q\) enters a region of constant, uniform and mutually orthogonal fields \(\overrightarrow E\) and \(\overrightarrow B\) with a velocity \(\overrightarrow v\) perpendicular to both \(\overrightarrow E\) a...

A charged particle moves through a magnetic field perpendicular to its direction. Then

A long straight wire of radius \(a\) carries a steady current \(i.\) The current is uniformly distributed across its cross section. The ratio of the magnetic field at \(a/2\) and \(2a\) is

A current \(I\) flows along the length of an infinitely long, straight, thin walled pipe. Then

Two identical conducting wires \(AOB\) and \(COD\) are placed at right angles to each other. The wire \(AOB\) carries an electric current \({I_1}\) and \(COD\) carries a current \({I_2}\). The magnetic field on a point lying at a distance $...

A long solenoid has \(200\) turns per \(cm\) and carries a current \(i.\) The magnetic field at its center is \(6.28 \times {10^{ - 2}}\,\,\,Weber/{m^2}.\) Another long solenoid has \(100\) turns per \(cm\) and it carries a current $${i \ov...

In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A charged particle is released from rest in this region. The path of the particle will be a

Two thin, long, parallel wires, separated by a distance \('d'\) carry a current of \('i'\) \(A\) in the same direction. They will

A charged particle of mass \(m\) and charge \(q\) travels on a circular path of radius \(r\) that is perpendicular to a magnetic field \(B.\) The time taken by the particle to complete one revolution is

Two concentric coils each of radius equal to \(2\) \(\pi\) \(cm\) are placed at right angles to each other. \(3\) ampere and \(4\) ampere are the currents flowing in each coil respectively . The magnetic induction in Weber / \({m^2}\) at...

A uniform electric field and a uniform magnetic field are acting along the same direction in a certain region. If an electron is projected along the direction of the fields with a certain velocity then

A long wire carries a steady current. It is bent into a circle of one turn and the magnetic field at the centre of the coil is \(B.\) It is then bent into a circular loop of \(n\) turns. The magnetic field at the center of the coil will be

The magnetic field due to a current carrying circular loop of radius \(3\) \(cm\) at a point on the axis at a distance of \(4\) \(cm\) from the centre is \(54\,\mu T.\) What will be its value at the center of loop?

A current \(i\) ampere flows along an infinitely long straight thin walled tube, then the magnetic induction at any point inside the tube is

Two long conductors, separated by a distance \(d\) carry current \({I_1}\) and \({I_2}\) in the same direction. They exert a force \(F\) on each other. Now the current in one of them is increased to two times and its direction is reversed. ...

A particle of mass \(M\) and charge \(Q\) moving with velocity \(\overrightarrow v\) describe a circular path of radius \(R\) when subjected to a uniform transverse magnetic field of induction \(B.\) The network done by the field when the ...

A particle of charge \(- 16 \times {10^{ - 18}}\) coulomb moving with velocity \(10m{s^{ - 1}}\) along the \(x\)-axis enters a region where a magnetic field of induction \(B\) is along the \(y\)-axis, and an electric field of magnitude $${...

If an electron and a proton having same momentum enter perpendicular to a magnetic field, then

The time period of a charged particle undergoing a circular motion in a uniform magnetic field is independent of its

If a current is passed through a spring then the spring will

If in a circular coil \(A\) of radius \(R,\) current \(I\) is flowing and in another coil \(B\) of radius \(2R\) a current \(2I\) is flowing, then the ratio of the magnetic fields \({B_A}\) and \({B_B}\), produced by them will be

Wires \(1\) and \(2\) carrying currents \(i{}_1\) and \(i{}_2\) respectively are inclined at an angle \(\theta\) to each other. What is the force on a small element \(dl\) of wire \(2\) at a distance of \(r\) from wire \(1\) (as shown in f...