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# Electric & Magnetic Fields

### Set of four problems on elecrostatics.

1) A charge +2q is placed at the origin and a second charge -q is placed at x = 3.0 cm. Where can a third charge +Q be placed so that it experiences a zero force? 2) A charge of -4.00 micro C is fixed in place. From horizontal distance of 55.0 cm, a particle of mass 2.50*10^-3kg and charge -3.00 micro C is fired

### Given the uniform charge density on two parallel sheets, find the magnitude of the net electric field.

Two very large parallel sheets are 5.00 cm apart. Sheet A carries a uniform surface charge density of -8.40 uC/m^2 , and sheet B , which is to the right of A , carries a uniform charge of -12.4 uC/m^2 . Assume the sheets are large enough to be treated as infinite. Find the magnitude of the net electric field these sheets prod

### A wall has a negative charge distribution producing a uniform horizontal electric field. A small plastic ball of mass 0.01 kg, carrying a charge of -80.0 µC, is suspended by an uncharged, nonconducting thread 0.30 m long. The thread is attached to the wall and the ball hangs in equilibrium (as show in the attachment)in the elastic and gravitational fields. The electric force on the ball has a magnitude of 0.032 N. Answer the following four questions.

A wall has a negative charge distribution producing a uniform horizontal electric field. A small plastic ball of mass 0.01 kg, carrying a charge of -80.0 µC, is suspended by an uncharged, nonconducting thread 0.30 m long. The thread is attached to the wall and the ball hangs in equilibrium (as show in the attachment)in the ela

### Infinitely long line of charge

An infinitely long line of charge has linear charge density 4.50×10^-12 Coulombs/m. A proton (mass 1.67×10^-27 kg, charge 1.60×10^-19 C) is 12.5 cm from the line and moving directly toward the line at 3000 m/s. 1) Calculate the proton's initial kinetic energy in J. 2) How close, in metres, does the proton get to the line

### Electric Field Between 2 Plates

A uniform, upward-directed electric field E of magnitude 2.00 x10^3 N/C has been set up between two horizontal plates by charging the lower plate positively and the upper plate negatively. The plates have length L=0.1m and separation d=0.02m. An electron is then shot between the plates from the left edge of the lower plate. The

### Equipotential Surfaces in an Electric Field

See the attached file. The dashed lines in the diagram represent cross sections of equipotential surfaces drawn in 1-V increments. a) What is the work W_AB in J done by the electric force to move a 1-C charge from A to B? b) What is the work W_AD in J done by the electric force to move a 1-rm C charge from A to D? c)

### Potential Difference - A spherical capacitor is formed from two concentric spherical conducting shells separated by vacuum.

A spherical capacitor is formed from two concentric spherical conducting shells separated by vacuum. The inner sphere has radius 10.0 centimeters, and the separation between the spheres is 1.50 centimeters. The magnitude of the charge on each sphere is 3.30 nanocoulombs. A) What is the magnitude of the potential difference De

### Electrostatics - Nonconducting Spheres

1. A nonconducting sphere has radius R=2.31cm and uniformly distributed charge q = +3.50fC. Take the electric potential at the sphere's center to be Vo = 0. What is V at radial distance (a) r =1.45cm and (b) r = R. ( answer is given as (a) is -0.268mV (b) -0.681mV, please show me the detail, thank you) 2. Two particles,

### The electric field between two charged disk

Two 10-cm-diameter charged disks face each other, 20 cm apart. The left disk is charged to - 50nC and the right disk is charged to + 50nC. a) What is the magnitude of the electric field vector in N/C at the midpoint between the two disks? b) What is the magnitude of the force F vector in N on a - 1.0nC charge placed at the m

### Two problems on electrostatics

1. Two charged concentric spherical shells have radii 10.0cm and 15.0cm. The charge on the inner shell is 4.00X10^-8C, and that on the outer shell is 2.00X10^-8C. Find the electric field (a) at r = 12.0cm and (b) at r = 20.0cm. 2, Two Large metal plates of area 1.0 m^2 face each other. They are 5.0 cm apart and have equal but

### Determining Ratio of Stored Energy: Example Problem

A slab of copper of thickness b = 1.167 mm is thrust into a parallel plate capacitor of C = 2.00×10-11 F of gap d = 7.0 mm, as shown in the figure (image attached); it is centered exactly halfway between the plates. What is the capacitance after the slab is introduced? If a charge q = 4.00×10-6 C is maintained on the plates,

### Gaussian Surface around the Room Air Volume Charge

When a shower is turned on in a closed bathroom, the splashing of the water on the bare tub can fill the room's air with negatively charged ions and produce an electric field in the air as great as 1000N/C.Consider a bathroom with dimensions 2.5m X 3.0m X2.0m. Along the ceiling, floor, and four walls, approximate the electric fi

### Electric Fields

A 43.2 nC Charge is located at position (x,y) = (1.0 cm, 2.0 cm). At what position (x,y) position is the electric field 1) At -225,000i N/C? 2) At (161,000i + 80,500j) N/C X=? Y=? 3) At (21,000i - 28,800j) N/C X=? Y=?

### Distance, acceleration, collision, force, strength of electric

1) The average distance an electron travels between collisions is 2.0 um. What acceleration must an electron have to gain 2.0 * 10^{ - 18} J of kinetic energy in this distance? 2) What force must act on the electron to give it that acceleration? 3) What strength electric field N/C will exert this much force on an electron?

### Calculating Magnitude and Direction of Electric Field

The electric potential V in the space between two flat parallel plates is given by V = 1300x^2 , where V is in volts if x, the distance from one of the plates, is in meters. Calculate the magnitude and direction of the electric field at x = 2.90 cm. What is the x-component of E?

### Determining electric field after spherical cavity is cut

A positive charge Q = 1600.00 C is uniformly distributed over the volume of a sphere of radius R = 5.00 m. Suppose a spherical cavity of radius R/2 is cut out of the solid sphere, the center of the cavity being a distance R/2 from the center of the original solid sphere (image attached). The cut-out material and its charge

### Magnitude of the electric field with distribution of charges

A. Calculate the magnitude of the electric field at the origin due to the following distribution of charges: +q at (x,y) = (a,a), +q at (a,-a), -q at (-a,-a) and -q at (-a,a). Where q = 2.25*10^-7C and a = 8.85 cm. B. (view image attached) Set up an 8-point compass at the origin, where north points along the positive y-axis,

### Electrostatics: Distance of Points Along the Axis

The E-Field at the center of a ring of charge is zero. At very large distances along the axis the E-field goes to zero. Find the distance of the points along the axis at which the E-field is a maximum. The radius of the ring is 5 cm and the total charge on the ring is .33 C.

### Magnetic Field due to a Current.

The problem states: Two semicircular arcs have radii R2 = 7.80 cm and R1 = 3.15 cm, carry current i = 0.281 A, and share the same center of curvature C. What are the (a) magnitude and (b) direction (into or out of the page) of the net magnetic field?

### Synchrotron for fixed target collisions

To achieve an energy of 20TeV, each of the SSC main rings contains approximately 4000 dipole magnets, each 16m long with a field of 7T. This means that over half of the 60mile SSC tunnel is taken up by dipoles. if you were to build a single synchrotron for use in fixed-target collisions of equivalent energy in the center-of-ma

### Electrostatic Charges & Fields

Problem 13 :- In figure 21-26 in attached file 3 particle 1 of charge +1.0 uC and particle 2 of charge -3.0 uC are held at separation L = 10.0cm on an x axis. If particle 3 of unknown charge (q3) is to be located such that the net electrostatic force on it from particles1 and 2 is zero. What must be the (a)x axis and (b) y

### Stoke's Vector Problem: Polarized Light

A light beam has a Stoke's vector of S = (1, 0.4, 0.2, 0). What is the Degree of Polarization? Would you characterize the light as linearly polarized or circularly polarized? What angle does the resultant electric field make with the horizontal axis?

### Current in a solenoid

What current is required in the windings of a long solenoid that has 1,000 turns uniformly distributed over a length of 0.400 m in order to produce a magnetic field of magnitude 1.00 x 10^-4 Tesla at the center of the solenoid?

### Protons Projected into Uniform Electric Field

A proton is projected in the positive x-direction into a region of uniform electric field, E = -6.0 x 10^5 i N/C at t = 0. The proton travels 7.0 cm as it comes to rest. Determine (a) the acceleration of the proton, (b) its initial speed, and (c) the time interval over which the proton comes to rest.

### Electric field due to a charged disc

A uniformly charged disk of radius 35.0 cm carries charge with a density of 7.90 x 10^-3 C/m^2. Calculate the electric field on the axis of the disk at (a) 5.0 cm, (b) 10.0 cm, (c) 50 cm and (d) 200 cm from the center of the disk.

### Deflection of electrons passing through magnetic field

In a television set, electrons are accelerated from rest through a potential difference of 19 kV. The electrons then pass through a 0.28 Tesla magnetic field that deflects them to the appropriate spot on the screen. What is the magnitude of the maximum magnetic force that an electron can experience?

### the angle between the wire and the magnetic field

A wire of length 0.655 m carries a current of 21.0 A. In the presence of a 0.470 T magnetic field, the wire experiences a force of 5.46 N. What is the angle (less than 90 degrees) between the wire and the magnetic field?

### Determining the change in potential energy of a proton

A uniform electric field, with a magnitude of 600 N/C, is directed parallel to the positive x-axis. If the potential at x=3.0 m is 1000 V, what is the change in potential energy of a proton as it moves from x=3.0 m to x=1.0 m? (qp= 1.6 x 10^-19C)? Vb-Va= -E(Sf-So)

### Distance covered by electron in electric field.

An electron with a speed of 2.0 x 10^6 m/s moves into a uniform electric field of 500 N/C that is parallel to the electron's motion. How far does the electron move before coming to rest? (me= 9.11 x 10^-31 kg, e= 1.6 x 10 -19 C). (Change in Kinetic Energy = change in Electrical Potential Energy)

### Electric Field and Stored Energy of Parallel-Plate Capacitor

A parallel-plate capacitor with plate area of 2 m^2 and a separation of 1.0 mm is charged to 100 V. (a) What is the electric field between the plates? (b) what is the energy per unit volume in the space between the plates? (c) find the total energy by multiplying your answer from part (b) by the total volume between the