Motion in a Magnetic Field

IMPORTANT

Motion in a Magnetic Field: Overview

This Topic covers sub-topics such as Motion of Charged Particle in Uniform Magnetic Field, Radius of the Helical Motion in Magnetic Field and, Pitch of the Helical Motion in Magnetic Field

Important Questions on Motion in a Magnetic Field

EASY
IMPORTANT

A particle having charge of 1 C, mass 1 kg and speed 1 m s-1 enters a uniform magnetic field, having magnetic induction of 1 T, at an angle θ=30°  between velocity vector and magnetic induction. The pitch of its helical path is (in meters)

EASY
IMPORTANT

Question Image
An electron gun G emits electron of energy 2 keV travelling in the (+)ve x-direction. The electrons are required to hit the spot S where GS=0.1 m & the line GS makes an angle of 60o with the x-axis, as shown in the fig. A uniform magnetic field B parallel to GS exists in the region outsides to electron gun. Find the minimum value of B needed to make the electron hit S.

EASY
IMPORTANT

A proton of mass m and charge +e is moving in a circular orbit in a magnetic field with energy 1 MeV. What should be the energy of α-particle (mass=4 m and charge=+2e), so that it can revolve in the path of same radius.

EASY
IMPORTANT

In the cyclotron, as radius of the circular path of the charged particle increases (ω= angular velocity, v= linear velocity)

EASY
IMPORTANT

In the cyclotron, as radius of the circular path of the charged particle increases (ω= angular velocity, v= linear velocity)

EASY
IMPORTANT

A particle of charge e and mass m moves with a velocity v in a magnetic field B applied perpendicular to the motion of the particle. The radius r of its path in the field is

EASY
IMPORTANT

A proton, a deuteron and an α-particle having the same kinetic energy are moving in circular trajectories in a constant magnetic field. If rp, rd and rα denote, respectively, the radii of the trajectories of these particles, then

EASY
IMPORTANT

A proton of mass m and charge +e is moving in a circular orbit in a magnetic field with energy 1 MeV. What should be the energy of α-particle (mass=4 m and charge=+2e), so that it can revolve in the path of same radius.

EASY
IMPORTANT

A particle of charge q and mass m, moving with a velocity v along the x -axis, enters the region x>0 with uniform magnetic field B along the k^ direction. The particle will penetrate in this region in the x -direction up to a distance d equal to

EASY
IMPORTANT

If a very high magnetic field is applied to a stationary charge then, the charge experiences no force.

MEDIUM
IMPORTANT

A charge enters a uniform magnetic field at an angle (0<θ<90). What will be the path of the charge? Also find its pitch?

MEDIUM
IMPORTANT

A charged particle with the charge to mass ratio qm=10319 C kg-1 enters in a uniform magnetic field B=(20i^-30j^+50k^) T at time t=0 with velocity v=(20i^+50j^+30k^) m s-1. Assume that magnetic field exists in large space. The pitch of the helical path of the motion of the particle is πn(in meter). Write the value of n.

HARD
IMPORTANT

Uniform electric and magnetic fields with strength E and induction B, respectively, are along y-axis as shown in figure. A particle with specific charge q/m leaves the origin O in the direction of x-axis with an initial non-relativistic velocity v0. The coordinate yn of the particle when it crosses the y-axis for the nth time is

Question Image

EASY
IMPORTANT

Discuss the motion of a charged particle the uniform magnetic field considering some angle between the magnetic field and velocity of the particle.

EASY
IMPORTANT

The kinetic energy of the emergent proton beam (in MeV) from a cyclotron oscillator having frequency of 12 MHz and dee radius 60 cm?q=1.6×10-19 C, mp=1.67×10-27kg and 1 MeV=1.6×10-13J 

MEDIUM
IMPORTANT

A proton, a deuteron and an α -particle with same kinetic energy enter perpendicularly in a uniform magnetic field. Then, the ratio of radii of their circular path is:

MEDIUM
IMPORTANT

An electron of energy 1800 eV describes a circular path in the magnetic field of flux density 0.4 T. The radius of the path is: q=1.6×10-19 C, me=9.1×10-31 kg

MEDIUM
IMPORTANT

The mass of a proton is 1847 times that of an electron. A electron and a proton are injected into a uniform electric field at right angle to the direction of the field with the same initial K.E.

EASY
IMPORTANT

In a crossed field, the magnetic field induction is 2.0T and electric field intensity is 20×103V/m . At which velocity the electron will travel in a straight line without the effect of electric and magnetic fields?

MEDIUM
IMPORTANT

An electron enters a region where magnetic field [B] and electric field [E] are mutually perpendicular, then