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

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.

The time period of ions in a cyclotron is independent of both the speed and radius of circular path.

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?

An electron is moving along the east to west direction in a uniform magnetic field which is along the south to north direction. In which direction will the electron experience force?

A metallic cube of side $15 \mathrm{cm}$ is moving along $y$-axis at a uniform velocity of $2 \mathrm{m} {\mathrm{s}}^{-1}$ in a region of uniform magnetic field of magnitude $0.5 \mathrm{T}$ directed along $z$- axis. In equilibrium the potential difference$\left(\text{in} \mathrm{mV}\right)$ between the faces of higher and lower potential developed because of the motion through the field will be.......

An electron is moving along the positive x-axis. If 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 electron will not experience any force in magnetic field

D.The electron will continue to move along the positive x-axis

E.The electron will move along circular path in magnetic field

Choose the correct answer from the option given below:

The source of time varying magnetic field may be

(A) a permanent magnet

(B) an electric field changing linearly with time

(C) direct current

(D) a decelerating charge particle

(E) an antenna fed with a digital signal

Choose the correct answer from the options given below.

An electron is moving along positive $x$ direction in $xy$ plane, magnetic field points in negative $z$ direction, then the force due to magnetic field on electron points in the direction

A wire$5 \mathrm{m}$long is supported horizontally at a height of $15 \mathrm{m}$ along east-west direction. When it is about to hit the ground, calculate the average e.m.f. induced in it. ($g=10 \mathrm{m} {\mathrm{s}}^{-2}$). The horizontal magnetic field is $B=3.6\times {10}^{-5} \mathrm{T}$