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# Electric & Magnetic Fields

### Quantum Mechanics Photons

The photon is normally assumed to have zero rest mass. If the photon had a small mass, this would alter the potential energy which the electron experiences in the electric field of the proton. Instead of V(r) = -(e^2)/(4(pi)(epsion_0)(r)) we would have V(r) = -((e^(2))(e^(-r/r_0)))/(4(pi)(epsilon_0)(r)) where r_0 is

### Electric field due to an infinite sheet

Consider a square plate whose sides have length l=20 cm with a total charge of +5.0 nC spread uniformly on its surface. What are the magnitude and direction of the electric field at a point 1.0 mm away from the plate's center?

### Problems with Electric Fields

A plastic ring of Radius R= 50.0 cm has two small charged beads on it. Bead 1 of charge +2.00 micro Coulombs is fixed in place on the left side of the ring. Bead 2 of charge +6.00 micro coulombs can be moved along the ring. The two beads produce a net electric field of magnitude E at the center of the ring. At what positive and

### Determining Electric Field Acting on Protons

Protons are projected with an initial speed v = 9550m/sec into region where the electric potential is given by V = 720z volts. The protons hit a target that lies a horizontal distance of 1.27 mm from the point where the protons are launched. Determine the electric field acting on the protons, and then find the two projection ang

### Magnetic force on rod on parallel conducting tracks

See attached file for diagram. Provide step by step calculations for the problem. Parallel conducting tracks, separated by 2.17 cm, run north and south (the figure below ). There is a uniform magnetic field of 1.25 T pointing upward (out of the page). A 0.0404-kg cylindrical metal rod is placed across the tracks and a batter

### Determining Induced Current: Example Problem

A wire of length 6 m has a total resistance of 12.8 Ω. The wire is initially made into a square loop and placed in a uniform magnetic field of strength 1.4 T, with the field perpendicular to the plane of the square loop. During the course of 0.2 s, the square loop changes into a rectangular loop with a 2:1 ratio of sides. What

### Electromagnetism: Force on charge moving in magnetic field

A positively charged particle of mass 7.28E-8 kg is traveling due east with a speed of 85.7 m/s and enters a 0.290 T uniform magnetic field. The particle moves through one-quarter of a circle in a time of 2.08E-3 s, at which time it leaves the field heading due south. All during the motion the particle moves perpendicular to the

### Direction of magnetic force exerted on electron

A wire is oriented along the z-axis, initially with no current in the wire. A moving electron is traveling along the x-axis in the positive direction. When the electron reaches the coordinate x = 4 m, a current in the wire suddenly is turned on, flowing in the +z direction. What is the direction of the magnetic force exerted on

### Electrostatics - Electric field at the centre of two squares

A square with sides of 2m has a line charge density of 3 uC/m throughout its four sides. It is inside a square with a line charge density of -2 uC/m, such that the two squares share the same center. This outer square has sides of 4m. What is the electric field at the center of the set up? Please give a step by step solution,

### Line with 2 Charges: Electric potential and electric field

Q7: A Line with 2 Charges Two equal and opposite charges are located on the x-axis. Which of the following statements are true about the electric potential and the electric field in the region surrounding the two point charges (at points A,B,C,D)? 1. T/F At point A, the electric field is zero. 2. T/F At point C, the electr

### Zero Electric Field for Three Point Charges

In the given figure, with three point charges placed along a line, is it possible to find a point where the combined electric field, due to the three charges, is zero (E = 0)? [Please refer to the attachment for the figure].

### Electric Field configuration in a region in space

Consider a region in space where a uniform electric field E = 500 V/m points in the negative x direction. Which of the following statements are true about this electric field configuration? 1- Equipotentials of 1000 V and 2000 V are separated by a distance of 2 m. 2-The magnitude of the electric field at x = 4 m is less

### Magnitude of the net electric field on the x-axis

Two equal positive charges (q1 = q2 = 3.2 &#956;C) are on the y-axis at +39.3 cm and -39.3 cm, respectively. What is the magnitude of the net electric field on the x-axis at x = 54.7 cm? Please explain and solve problem.

### Physics: Lorentz force and behavior of current carrying conductors in a magnetic field.

You will run a simulation of Lorentz force exerted on a current carrying conductor located in the magnetic field of a horseshoe magnet. The experiment is set up so that you can change the direction of polarity of the magnet and the direction of the current as well as turn the current on and off. Click on the following link t

### Magnetic Field Between Two Wires: Determine the magnitude

Part 1 Determine the magnitude of the magnetic field midway between two long straight wires 2.00 cm apart when one wire carries 4.10 A and the other carries 15.8 A. Assume these currents are in the same direction. Part 2 Determine the magnitude of the magnetic field when these currents are in opposite directions P

### Estimate the current in the wire if the field is 0.137 T.

The force on a wire is a maximum of 4.66 N when placed between the pole faces of a magnet. The current flows horizontally to the right and the magnetic field is vertical. The wire is observed to "jump" toward the observer when the current is turned on. If the pole faces have a diameter of 13.5 cm, estimate the current in the wir

### Force on Particle Moving an Angle Relative to Magnetic Field

A particle with a charge of 15.3 &#956;C experiences a force of 2.43E-4 N when it moves at right angles to a magnetic field with a speed of 22.2 m/s. What force does this particle experience when it moves with a speed of 6.04 m/s at an angle of 23.5 ° relative to the magnetic field? Please explain and solve problem.

### Parallel Plate Capacitor: potential difference; magnitude of a uniform electric field

Part 1 A parallel-plate capacitor has an area of 5.19 cm2, and the plates are separated by 1.06 mm with air between them. It stores a charge of 334 pC. What is the potential difference across the plates of the capacitor? (in V) Part 2 What is the magnitude of the uniform electric field in the region between the plates

### Physics: Electric Field, strength, charge, intensity

The answers are included but the workings are needed. Electric Field 1. What is the field strength at a reference point if a force of 40N is necessary to hold a charge of 200uC at that point? Answer: 2 x 105 N/C 2. A charge of -2 x 10-9C in an electric field between two parallel metal plates 4cm apart is acted upon by

### Physics: Which statements are true about Magnetic forces

Which of the following statements are true about magnetic forces acting on charged or uncharged particles? Choose True or false for the following statements. True False the magnetic force always acts parallel to the direction of motion of the moving charged particle. True False the maximum magnetic force that a charged

### Electric field and Potential: Parallel plate capacitor.

Part 1 Consider the Earth and a cloud layer 760 m above the Earth to be the plates of a parallel-plate capacitor. If the cloud layer has an area of 1.03 km2 = 1.03E+6 m2, what is the capacitance? Part 2 If an electric field strength greater than 4.29E+6 N/C causes the air to break down and conduct charge (lightning), w

### Electric Field and Voltage

An electric field of 370 V/m is desired between two parallel plates 12.1 mm apart. How large a voltage should be applied? -Please provide a detailed explanation and include numerical solution and signs (If positive or negative).

### Physics: Electric Field a the Mid-Point of Two Charges

The electric field midway between two equal but opposite point charges is 1870 N/C, and the distance between the charges is 19.2 cm. What is the magnitude of the charge on each? -Please show all steps including numerical solution.

### Capacitor: Electric Potential and Field

Two parallel plates, separated by 10 mm, are charged to a potential difference of 50 V (that is, one plate is 0 V and the other plate is 50 V). Which of the following statements are true? True False the electric field between the plates is 5000 V/m True False the electric potential at the midpoint between the plates is

### Zero Electric Field

A positive point charge Q1 = 2.33E-5 C is fixed at the origin of coordinates, and a negative charge Q2 = -3.63E-6 C is fixed to the x axis at x = +2.13 m. Find the location of the place along the x axis where the electric field due to these two charges is zero. Please explain the problem

### Electric Field at the Center of a Square Calculation

Calculate the magnitude of the electric field at the center of a square with sides 24.2 cm long if the corners, taken in rotation, have charges of 1.14 mC, 2.28 mC, 3.42 mC, and 4.56 mC (all positive). Please explain the problem.

### Electric Field a the Mid-Point of Two Charges

The electric field midway between two equal but opposite point charges is 1870 N/C, and the distance between the charges is 19.2 cm. What is the magnitude of the charge on each? -please explain the problem

### Fifteen Questions: Electric Field and Potential.

Problem 1 A charge is moved from one place to another in an electric field. In which of the following situations will the change in potential energy be NON-ZERO? the charge is only moved perpendicular to all electric field lines that it crosses the charge remains unmoved the charge is moved along an equipotential surfa

### Method of images..

Problem with diagram is attached. Consider a dipole above an infinite grounding plane as shown (attachment). Plot the induced surface charge sigma (x,0,0) for (-15A<x<15A). Try to sketch what you think it will look like before you calculate it. What do you think sigma (0,0,z) for (-15A<x<15A) will look like?

### Capacitance formula

The space between the plates of a parallel-plate capacitor with plate separation s and surface area S is partially with a dielectric plate of area S and of thickness t<s. Show that the capacitance is: epsilon_o*S/s-[(epsilon_r - 1)t/epsilon_r]