Exam 18: Electric Forces and Electric Fields

The figure shows a parallel plate capacitor. The surface charge density on each plate is 8.8 × 10^-8 C/m². The point P is located 1.0 × 10^-5 m away from the positive plate. -What is the magnitude of the electric field at the point P?

Four point charges are placed at the corners of a square as shown in the figure. Each side of the square has length 2.0 m. Determine the magnitude of the electric field at the point P, the center of the square.

An electron traveling horizontally enters a region where a uniform electric field is directed upward. What is the direction of the force exerted on the electron once it has entered the field?

Which one of the following statements is true concerning the spacing of the electric field lines in the vicinity of two point charges of equal magnitude and opposite sign?

A straight, copper wire has a length of 0.50 m and an excess charge of -1.0 × 10^-5 C distributed uniformly along its length. Find the magnitude of the electric field at a point located 7.5 × 10^-3 m from the midpoint of the wire.

A charged conductor is brought near an uncharged insulator. Which one of the following statements is true?

A conducting sphere has a net charge of -6.4 × 10^-17 C. What is the approximate number of excess electrons on the sphere?

Which one of the following statements is true concerning the electrostatic charge on a conductor?

A solid, conducting sphere of radius a carries an excess charge of +6 µC. This sphere is located at the center of a hollow, conducting sphere with an inner radius of b and an outer radius of c as shown. The hollow sphere also carries a total excess charge of +6 µC. -Determine the excess charge on the inner surface of the outer sphere (a distance b from the center of the system).

One mole of a substance contains 6.02 × 10²³ protons and an equal number of electrons. If the protons could somehow be separated from the electrons and placed in very small, individual containers separated by a million meters, what would be the magnitude of the electrostatic force exerted by one box on the other?

Two particles of the same mass carry charges +3Q and -2Q, respectively. They are shot into a region that contains a uniform electric field as shown. The particles have the same initial velocities in the positive x direction. The lines, numbered 1 through 5, indicate possible paths for the particles. If the electric field points in the negative y direction, what will be the resulting paths for these particles?

Two positive point charges Q and 2Q are separated by a distance R. If the charge Q experiences a force of magnitude F when the separation is R, what is the magnitude of the force on the charge 2Q when the separation is 2R ?

Complete the following statement: The magnitude of the electric field at a point in space does not depend upon

Complete the following statement: When an ebonite rod is rubbed with animal fur, the rod becomes negatively charged as

A conducting sphere carries a net charge of +6 µC. The sphere is located at the center of a conducting spherical shell that carries a net charge of -2 µC. Determine the excess charge on the outer surface of the spherical shell.

The figure shows an equilateral triangle ABC. A positive point charge +q is located at each of the three vertices A, B, and C. Each side of the triangle is of length a. A point charge Q (that may be positive or negative) is placed at the mid-point between B and C. -Is it possible to choose the value of Q (that is non-zero) such that the force on Q is zero? Explain why or why not.

Two point charges, A and B, lie along a line separated by a distance L. The point x is the midpoint of their separation. -Which combination of charges will yield zero electric field at the point x?

Two uncharged conducting spheres, A and B, are suspended from insulating threads so that they touch each other. While a negatively charged rod is held near, but not touching sphere A, someone moves ball B away from A. How will the spheres be charged, if at all?

In the figure, point A is a distance L away from a point charge Q. Point B is a distance 4L away from Q. What is the ratio of the electric field at B to that at A, E_B/E_A?

Five particles are shot from the left into a region that contains a uniform electric field. The numbered lines show the paths taken by the five particles. A negatively charged particle with a charge -3Q follows path 2 while it moves through this field. Do not consider any effects due to gravity. -What is the magnitude of the electric field due to a 6.0 × 10^-9 C charge at a point located 0.025 m from the charge?