PHYS-1602 Chapter Notes - Chapter 22: Electric Field, Electric Dipole Moment

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violethyena861

9 May 2016

School

Vanderbilt University

Department

Physics

Course

PHYS-1602

Professor

Grundstrom Erika

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Document Summary

E = f / q (not) formula for an electric field (n/c) **if its in the direction of the electric field, its positive, if force is not in the direction of e, it is negative. **for negative objects, lines go towards (field,) and for positive they go out (field) (electric field lines extend away from positive charge (where they originate) and toward negative charge (where they terminate)) Finding magnitude of e due to a charged particle: e = k ([q]/r^2) To find the elcectric field at a given point when there are many charged particles, find the f due to each particle and then plug it into e = f/q and add them all up as vectors. *to add vectors, use cos for x part and sin for y part electric dipole: two particles with same charge magnitude but opposite sides, lie on z axis. E = (1/2*pi*epsnot)(p/z^3) electric dipole where p = qd (electric dipole moment).

Related Questions

Which of the following statements are not true for electric field lines?

(A) Electric field lines are close together in regions of space where the magnitude of the electric field is strong and are farther apart where it is weak.

(B) Electric field lines can never intersect.

(C) At every point in space, the electric field vector at that point is tangent to the electric field line through that point.

(D) Electric field lines are close together in regions of space where the magnitude of the electric field is weak and are farther apart where it is strong.

(E) Electric field lines point away from positive charges and toward negative charges.

(F) Electric field lines are continuous; they do not have a beginning or an ending.

(G) At every point in space, the electric field vector at that point is perpendicular to the electric field line through that point.

byzantiumtiger439

1.Two uncharged, conducting spheres, A and B, are held at rest oninsulating stands and are in contact. A positively charged rod isbrought near sphere A. While the rod is in place, the two spheresare separated. How will the spheres be charged, if at all, afterthey are separated?
Sphere A Sphere B
(a) positive positive
(b) positive negative
(c) negative positive
(d) negative negative
(e) zero zero

2. A charged conductor is brought near an uncharged insulator.Which one of the following statements is true?
(a) Both objects will repel each other.
(b) Both objects will attract each other.
(c) Neither object exerts an electrical force on the other.
(d) The objects will repel each other only if the conductor has anegative charge.
(e) The objects will attract each other only if the conductor has apositive charge.

3. An electron is moved from point A, where the electric potentialis VA = â240 V, to point B, where the electric potential is VB =â360 V. What is the change in the electric
potential energy?
(a) 1.92Ã10â17 J (b) 2.04Ã10â17 J (c) 5.75Ã10â17 J (d) 8.98Ã10â17 J(e) 1.05Ã10â16 J

4. A -2q charge is located a distance d to the right of a +4qcharge, along the x
axis. At which point (or points) along the axis does the electricfield go to zero? To
solve this problem, consider an observer at point P, which is anarbitrary distance x from the +4q charge. Find the value (orvalues) for x (in terms of the separation distance d) where thetotal electric field vanishes.
(a) The electric field is never zero in the vicinity of thesecharges.
(b) The electric field is zero at x = -0.328d.
(c) The electric field is zero at x = +4.22d.
(d) The electric field is zero at both x = -2.26d and x =+2.26d.
(e) The electric field is zero at x = +3.41d.

5. point A is a distance L away from a point charge Q. Point B is adistance 4L away from Q. What is the ratio of the electrostaticpotential at B to that at A, i.e., what is VB/VA?
(a) 1/16
(b) 1/9
(c) 1/4
(d) 1/3
(e) can not be determined without specifying Q and L

6. Which one of the following statements best explains why it ispossible to define an electric potential
in a region of space that contains an electric field?
(a) Work must be done to bring two positive charges closertogether.
(b) Like charges repel one another and unlike charges attract oneanother.
(c) A positive charge will gain kinetic energy as it approaches anegative charge.
(d) The work required to bring two charges together is independentof the path taken.
(e) A negative charge will gain kinetic energy as it moves awayfrom another negative charge.