Magnetic Force

An electron moving with a velocity ${\overrightarrow{\text{V}}}_1=\text{2}\widehat{\text{i}}\text{m}/\text{s}$ at a point in a magnetic field experiences a force ${\overrightarrow{\text{F}}}_1=-2\widehat{\text{j }}\text{N}$ . If the electron is moving with a velocity ${\overrightarrow{\text{V}}}_2=\text{2}\widehat{\text{j}}\text{m}/\text{s}$ at the same point, it experiences a force ${\overrightarrow{\text{F}}}_2=+2\widehat{\text{i}}\text{N}$ . The force the electron would experience if it were moving with a velocity ${\overrightarrow{\text{V}}}_{\text{3}}=\text{2}\widehat{\text{k}}\text{m}/\text{s}$ at the same point is

A charged particle is released from rest in a region of uniform electric and magnetic fields, which are parallel to each other. The locus of the particle will be

$\mathrm{OABC}$ is a current-carrying square loop. An electron is projected from the centre of the loop along with its diagonal $\mathrm{AC}$ as shown. The unit vector in the direction of initial acceleration is

Infinite number of straight wires each carrying current I are equally placed as shown in the figure. Adjacent wires have current in opposite direction. Net magnetic field at point P is.

A charge particle $A$ of charge $q=2 \mathrm{C}$ has velocity $v=100 \mathrm{m} {\mathrm{s}}^{-1}$. When it passes through point $A$ and has velocity in the direction shown. The strength of magnetic field at point $B$ due to this moving charge is $(r=2 \mathrm{m})$.

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 XX' is given by

The figure shows a conductor of weight 1.0 N and length L = 0.5 m placed on a rough inclined plane making an angle ${\text{30}}^{\text{o}}$ with horizontal so that conductor is perpendicular to a uniform magnetic field of induction B = 0.1T. The coefficient of static friction between the conductor and the plane is 0.1, A current of I = 10A flows through the conductor inside the plane of this
paper as shown.
What is the force needed to be applied parallel to the inclined plane to sustain the conductor at rest.

A circular coil, of radius $R$, carries a current $I$. The expression for the magnetic field due to this coil at its centre is

A beam of electrons projected along + x – axis, experiences a force due to a magnetic field along the +y – axis. The direction of the magnetic field is:

A beam of  $\alpha$  particles projected along +x – axis, experiences a force due to a magnetic field along the +y – axis. What is the direction of the magnetic field?
 

An electron moves around the nucleus in a hydrogen atom of radius $0.51 \stackrel{\circ }{\mathrm{A}}$, with a velocity of  $2\times {10}^5 \mathrm{m} {\mathrm{s}}^{-1}$. Calculate the following :

(i) The equivalent current due to orbital motion of electron.

(ii) The magnetic field produced at the centre of the nucleus.

(iii) The magnetic moment associated with the electron.

A circular coil of 200 turns and radius 10 cm is placed in a uniform magnetic field of 05. T, normal to the plane of the coil. If the current in the coil is 3.0 A, calculate the

(a) Total torque on the coil.

(b) Total force on the coil.

(c) Average force on each electron in the coil, due to the magnetic field.

Assume the area of cross – section of the wire to be  ${10}^{-5}$  ${\text{m}}^{\text{2}}$  and the free electron density is  ${10}^{29}/{\text{m}}^3$ .

An electron is moving along +ve x-axis in the presence of uniform magnetic field along +ve y-axis. What is the direction of the force acting on it?

In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an electric potential $\mathrm{V}$ and then made to describe semicircular paths of radius $\mathrm{R}$ using a magnetic field $\mathrm{B}$. If $\mathrm{V}$ and $\mathrm{B}$ are kept constant, the ratio $\left(\frac{\text{ Charge on the ion }}{\text{ mass of the ion }}\right)$ will be proportional to:

What is the unit of magnetic field intensity?

The electron in the beam of a television tube move horizontally from south to north. The vertical component of the earth's magnetic field points down. The electron is deflected towards,

An electron and a proton travel with equal speed in the same direction at $90°$ to a uniform magnetic field as this is switched on. They experience forces which are initially

An electron enters a region of magnetic field.

In which case is the initial force on the electron directed towards the bottom of the page?

A moving electron enters normally into a uniform magnetic field; its: