Lorentz Force

Author:Embibe Experts
12th Tamil Nadu Board
IMPORTANT

Important Questions on Lorentz Force

MEDIUM
IMPORTANT

A particle of mass m, carrying charge q is accelerated through a potential of VVolt. When this accelerated charge comes under the influence of perpendicular magnetic field, the force acting on it is:

HARD
IMPORTANT

The period of revolution of a charged particle inside a cyclotron does not depend on:

HARD
IMPORTANT

Which of the following is the correct expression of the velocity selector?

HARD
IMPORTANT

A particle having mass m and charge q is released from the origin in a region in which electric field and magnetic field are given by
B=-B0j and E=E0k.
Find the speed of the particle as a function of its z-coordinate.

HARD
IMPORTANT

Describe the working of cyclotron. Draw the diagram showing path of particle in both "Dees" Derive expression for frequency of cyclotron.

MEDIUM
IMPORTANT

In the given figure, an electron moves at speed v=100 m s-1 along an x-axis, through uniform electric and magnetic fields. The magnetic field is directed into the page and has magnitude 5.00 T. In unit-vector notation, what is the electric field?

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EASY
IMPORTANT

If instead of electron a neutron enters a field, what will be its direction of motion? Give reasons for your answer.

HARD
IMPORTANT

(a)A monoenergetic electron beam with electron speed of 5.20×106 m/s is subject to a magnetic field of 1.30×10-4 T normal to the beam velocity. What is the radius of the circle traced by the beam, given em for electron equals 1.76×1011 CKg-1.

(b)Is the formula you employ in (a) valid for calculating radius of the path of a 20 MeV electron beam? If not, in what way is it modified?

EASY
IMPORTANT

Answer the following question:
Interstellar space has an extremely weak magnetic field of the order of 10-12 T. Can such a weak field be of any significant consequence? Explain.

HARD
IMPORTANT

A magnetic field set up using Helmholtz coils is uniform in a small region and has a magnitude of 0.75 T. In the same region, a uniform electrostatic field is maintained in a direction normal to the common axis of the coils. A narrow beam of (single species) charged particles all accelerated through 15 kV enters this region in a direction perpendicular to both the axis of the coils and the electrostatic field. If the beam remains undeflected when the electrostatic field is 9×10-5 Vm-1, make a simple guess as to what the beam contains. Why is the answer not unique?

EASY
IMPORTANT

A charged particle enters an environment of a strong and non-uniform magnetic field varying from point to point both in magnitude and direction and comes out of it following a complicated trajectory. Would its final speed equal the initial speed if it suffered no collisions with the environment?

EASY
IMPORTANT

A magnetic field that varies in magnitude from point to point but has a constant direction (east to west) is set up in a chamber. A charged particle enters the chamber and travels undeflected along a straight path with constant speed. What can you say about the initial velocity of the particle?

EASY
IMPORTANT

In a certain region of space, electric field E and magnetic field B are perpendicular to each other and an electron enters in the region perpendicular to the direction of B and E both and moves undeviated, then velocity of electron is -

MEDIUM
IMPORTANT

A charged particle with charge q enters a region of constant, uniform and mutually orthogonal fields E and B   with a velocity ν   perpendicular to both E   and B , and comes out without any change in magnitude or direction of ν . Then,

EASY
IMPORTANT

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, 

EASY
IMPORTANT

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

MEDIUM
IMPORTANT

If an electron and a proton having the same momentum enter perpendicular to a magnetic field, then_____.