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Electricity & Magnetism

Electric and magnetic field problem

Four charges are moving with constant velocity v along the sides of a square as it is shown in attached the diagram. The side length is a. Determine the magnitude and direction of electric and magnetic fields by these charges at an instant when they are exactly in the middle between two consequent corners. Please explain how

Disc in a magnetic field

Given an aluminum disc of radius R, thickness d, conductivity , and mass density spins on its axis with initial velocity . It passes through poles of a magnet producing a magnetic field perpindicular to the disc over a small area A. With this initial speed how many revolutions will it make before coming to rest?

Gravitational Field

What is the gravitational field both inside and outside a soherical shell of inner radius b and outer radius a?

Motion of a charge particle in Magnetic and electric field.

A positive ion with charge 4.8 x 10(-19) C is traveling at a speed of 3 x 10(7) ms(-1) above the earth's atmosphere from East to West along the equator. The earth's magnetic field runs North-South. 1) Draw a sketch showing clearly the direction of motion of the charge, the lines of magnetic force and the direction of the magn

Electric Current and Magnetism

I need some help with these question: Two long, straight wires are oriented perpendicular to the computer screen, as shown below, in which L = 4.5 cm. The current in one wire is I1 = 3.1 A, pointing into the screen, and the current in the other wire is I2 = 4.0 A, pointing out of the screen. Find the magnitude and direction of

2 Electromagnetic Questions

Question: For an accelerating voltage of 900 V calculate the time taken for an electron to reach the anode after being accelerated from rest (u=0) at the cathode of a CRT. Anode -cathode separation is 1cm? Question: A wire carrying a current of 100 A due West in Australia is suspended between two towers 50 m apart. The lines

Megnetic effect of electric current: Field due to 4 wires.

"Consider the four current-carrying wires described in the figure below. Each of these wires is long and straight, and carries the current I either into or out of the page, as shown." What is the direction of the net magnetic field produced by these four wires at the center of the square? Please see attached for diagram.

Electron Volt

What is the speed of a 300-eV proton? What is the speed of a 300-eV electron? Key: 2.40x10^5, 1.03x10^7

Magnetic Field

In a region of space, the magnetic field increases at a constant rate. This changing magnetic field induces an electric field that (a) increases in time (b) is conservative (c) is in the direction of the magnetic field (d) has a constant magnitude. And why explain? Induced electric field E in Equation 31.9 (see attachment) is

Crossed Electric and Magnetic Fields

Show how an undeflected trajectory for a moving charge is obtained with appropriate crossed E and B fields. Draw seperate diagrams to illustrate your answer for a positive charge and a negative charge.

Electric and Magnetic Fields

A magnetic field has a magnitude of 12 T. What is the magnitude of an electric field that stores the same energy per unit volume as this magnetic field?

Magnetic Field

A 1140nF capacitor with circular parallel plates 1.12cm in diameter is accumulating charge at the rate of 20.7mC/s at some instant in time. What will be the induced magnetic field strength 10.8cm radially outward from the center of the plates? What will be the value of the field strength after the capacitor is fully charged?

Earth's magnetic field

Differentiate between the Earth's magnetic field and its production versus that of an ordinary bar magnet.

Proton source: Speed of the protons, radius of the final path

See attached file for the diagram. A proton source provides protons of various speeds. Protons of a particular speed follow the dotted line through the speed selector. The speed selector has an electric field of 3100 V/m and a magnetic field of 0.35T. The protons that the speed selector selects follow the dotted path.


A copper sulfate solution is placed in a container that contains coaxial cylindrical copper electrodes, as indicated in the picture. An electric field is created by connecting a battery across the electrodes as shown. A magnet field is created by immersing a magnet in the center of the solution as shown. Uncharged pollen g